Rather than go on about World Wars and superior technology here is a greentext about a topical war which Celestia might find more...relevant. Its also horribly under appreciated. The English Civil War. If you don't know much about it I would recommend reading more (even if you just want to better understand the greentext)
https://en.wikipedia.org/wiki/Wars_of_the_Three_Kingdoms


>Being called alone to a meeting with Celestia and "important individuals" was ominous enough.
>You and Celestia had a...lively relationship.
>You both vehemently disagreed on just about everything and routinely debated and fought about anything and everything relevant or not.
>Honestly you just like arguing, and you never really lost your old political, economic, social, and religious ideas from Earth.
>Still, it was always civil and shouting matches were rare.
>Plus you were a decent writer and you actually did a bit of  good proposing some (heavily altered by Equestrian circumstances) organizations and institutions, so at least that kept you tolerable to Celestia.
>Still, being summoned in the ungodly early hours of the morning is never good.
>You were ushered into the castle and down flights upon flights of stairs until you reached a room strewn with maps and lined with a cast of your least favorite Equestrian individuals.
>Luna "ye olde" princess of the moon.
>Celestia "believes her own propaganda" princess of the sun.
>Purple Smart, Blueblood, Cadence, and Shining Armor were there.
>You were about to ask what you were doing up before noon, when Celestia took the initiative.
>"Anon, I know you dislike unnecessary formality so...Anon, I...don't know if I should ask this of you, but I fear that desperate times call for desperate measures. The Griffons, the Minotaurg, and the Diamond Dogs have already conquered our allies in Saddle Arabia. The Crystal Empire is facing internal turmoil. Equestria stands alone. Humans are well versed in warfare. We need a weapon to change the outcome of this terrible war. Please, will you help us?

"You know I'm not a warrior, so presumably you want someone who can organize things?"
>"You're not a warrior?, given your total barbarity you could have fooled me, I'm positive everypony thinks you have a penchant for violence you insect."
>Blueblood is such a cunt.
"Maybe I'm not particularly strong and am only an insect, just remember that even insects can kill parasites."
>Celestia already was loosing her patience.
>"Enough of this bickering. Anon, if you accept your job would be to facilitate a total military reorganization in equipment and doctrine. You would have the full resources of the crown to help with whatever you saw fit."
"If you give me this position many will not like it. I will need total freedom and commitment of resources, both physical and political support to back it up. You will have to grant me power many will find unsettling. I will deliver you a military force capable of defeating the marauding invaders, but in doing so your society will totally change. The populace do not quickly forget the power they wield through a citizen army, the effects on the economy that military production will have, the diplomatic arena will change, and much more I can't even begin to imagine."
>You begin to walk out of the room.
"I'm going to take an early breakfast. I ask that you have an answer for this question when I return. Are you willing to grant me unlimited power in military affairs with participatory power in diplomatic and economic affairs in order to help organize a human-style military which will secure your objective?"
>You turn your back and leave for some overpriced breakfast in Canterlot.

>You walk into the first open, overpriced place.
>You never ate much in the morning, so you sat down and were attended to by a posh waiter.
>You spent most of the time pony watching.
>Fat, useless, parasitic nobles with bygone titles and pedigrees of accomplishments long past sat meters away from you.
>Turning your head 45 degrees you could see Canterlot's lower districts with people who would give up a lot to have a breakfast of such a high quality.
>You simply sighed, finished your light meal, and began walking towards the castle.
>As you departed you heard poorly hushed whispers from ponies about you, "political radical", "crazed economist", "insane innovator", were the friendliest of the things you heard.
>You returned to the castle and you were greeted by...saluting.
>Well then...
>You walked through the castle with no objections and only salutes.
>Some of the "noble" soldiers clearly didn't want to salute you, doing their best to glare at you as they saluted.
>Returning toothy grins usually set them forward at attention.
>After asking for directions you walked into the war room to see everyone from before, and a few new faces, in silence simply looking at maps.
>All of them looked pretty depressed.
"I would ask for an answer to your question from before, but given that I was saluted rather than barred I suppose you have accepted my conditions and have informed everypony?"
>"Anonymous I accept your offer with one condition, the pre-existing high noble council and..."
"No. Unacceptable. My employment comes with no conditions, no bargains. You want a council that can reject my actions when they see fit, correct? Imagine the military like a machine, the fewer moving pieces, the better because less can go wrong or slow down decision making. If you insist on making my job harder I won't take it, get another to fight your war."
>In another life you would have been a great politician. Or maybe an actor.
>You turn your back and begin walking out the door.
>Any second now...
>"Wait."

>You turn around and do you best to fight off the grin you want to bear.
>"We accept you conditions."
"I see no reason to wait, let us begin right now."
"First thing is first. I need an adjutant who is an organizational and scientific mastermind. Somepony who is open minded and knowledgeable, and can second guess me when appropriate. Somepony who will have a wide breadth of knowledge."
>"Shining Armor would make..."
>You think that is the first time you have ever heard Luna lack confidence or volume.
"No. I already have a different job for him. I want Shining Armor to be my direct liaison between myself and the military organization I shall create. I already know who I want for my adjutant."
>You turn away from Luna and look at Celestia right in the eyes.
"I want Twilight Sparkle."
>"Twilight Sparkle is an academic, not a..."
"The best MINDS win wars. The more thinking, sweating, and planning one does off the battlefield the less bleeding does on the battlefield."
>Extensive historical knowledge and all those RTS games finally amount to something other than crippling social anxiety Anon, good job.
"You have just granted me unlimited power in military affairs. IF I AM GOING TO BE SECOND GUESSED AT EVERY SINGLE JUNCTION WITH EVERY SINGLE DECISION I SWEAR I WILL RESIGN RIGHT NOW AND YOU CAN GET SOMEONE ELSE TO SAVE YOUR NATION!."
>Celestia seems taken aback at your anger.
>Directed anger certainly helps win arguments occasionally.
"My apologies at the outburst, but I know what I am doing. I don't intend on sending Twilight to the front-lines to fight the enemy off alone, you need not worry for her safety."
"Now, there are many more things which need to happen during this first meeting."
>Twilight herself was quiet during this.
>At first she was surprised.
>Now she looks...resolute.
"After this wider meeting, Twilight, Shining Armor, and myself will need to have a smaller meeting to begin hammering out the finer details of our opening actions."

"While I dislike nobility I acknowledge in your society they have their uses and benefits. Therefore I will need a granted title to legitimize my command."
>You can see Blueblood tense up and open his mouth to speak.
"Relax, I don't need any lands, or any pension beyond covering my living expenses. I also don't need an existing title so you don't have to worry about offending the existing nobility. I would require a new title. How about... Lord Protector."
>"Done. I dub (checkem) thee Lord Protector Anonymous of Equestria"
"Thank you Celestia. To whoever in this room can do something legal, I will need that title officially announced and written down for all to understand by today."
>As you hear somepony scurry out of the room you give your best shit eating grin to Blueblood.
"Now, next we need to send a message both to Equestria and our enemies that the Royal Guard is gone, and a new more powerful force is in its stead. I will need to meet with a person who can make heraldics after this, so whoever is currently gathering people please go do that."
>Again somepony scurries out of the room.
"I hereby rename the Royal Guard... The New Model Army. Any objections?"
>None. Of course they don't get the significance of a Lord Protector leading a New Model Army, heh.

"First we need to buy time."
>You point to several locations on the map.
"Given the geography and roads, these are the most likely axises of the enemy advance. The existing Royal Guard units are to head to these areas, evacuate all civilians within 100km of the roads, and then conduct a scorched Earth retreat."
>"Scorched Earth?"
"Every well, every grain silo, every field, every orchard, any resources which would aid the invaders and give them rest or comfort, must be burned. This will slow their advance as their logistics struggle to catch up.
>You can tell that almost everypony wanted to speak up, but none dared at this point, even the princesses seemed reluctant.
>A person without friends is without power, better explain a bit.
>Don't want to blow up more bridges than the Wehrmacht.
"As adept as I am I need time, time is a resource we are sorely lacking. This will buy us time. Consider this a tragically necessary amputation required to save a patient's life. I wish this wasn't necessary, but..."
>You intentionally look despondent for a few seconds before restarting.
"Until the arrival of my primary adjutant there is nothing more we can accomplish here talking, so let us begin acting. I will organize the first moves with Captain Shining Armor. The council is adjourned."
>With that you begin to walk up the spiral staircase, frenzied activity left in your wake.

>The meeting with Twilight and Shining Armor was tedious, but necessary.
>Twilight was up to the tasks you through she was, effortlessly ushering in officials as they were required and knowing exactly where in the bureaucracy or economy to go to get something done.
>First and foremost the New Model Army had to have new armor, weapons, and doctrines.
>Spears were out, Halberds and Poleaxes were in.
>Swords were now sidearms.
>Crossbows were in en-masse.
>Anypony could point and shoot one with some training.
>The gallant individual standing alone was gone, replaced with fighting units.
>Warriors and chivalrous champions were to be replaced with soldiers.
>What a happy coincidence that these "easy" ways of fighting would help to displace the old noble dominated warrior and mage-warrior and ushered in a more citizen-oriented meritocratic and egalitarian tradition.
>The regal and splendid old Royal Guard uniforms were replaced with a metallic grey with grey coats interspersed with chainmail.
>When nopony knew what chainmail was you were annoyed that you had to draw up a design, but the armorer looked as if he had a revelation and promised that they could be easily reproduced.
>Grey was not only cheap and blended in with metal, but also blended in far better than shining gold or pristine white with most environments.
>You had to meet with the armorer and draw out basic designs for chainmail and halberds, but at least it was done quickly thanks to Shining Armor knowing how to weight specific ends for Earth Ponies.
>You even explained and drew the mechanics of guns. You were no engineer however and the enemy was fast approaching, so it was put on the back-burner for now.

>The most important thing which would make or break the New Model Army's future was its ability to adopt new doctrines.
>The average magical skill and biological capacity of unicorns meant that most were unsuited to being full on battle mages, but were suited to being communicators, messengers, and coordinators.
>In an essentially medieval battlefield Unicorns could provide instantaneous communication, yet they had seldom been utilized in such a way and never been used in such a way en-masse.
>Pegasi were to transform from being the primary airborne melee units which made up the main air element of the Equestrian Royal Guard, a pseudo Equestrian warrior caste unto itself, to skirmishers, scouts, vanguards, and raiders.
>Earth ponies armed en-masse with crossbows and halberds could rain death upon enemies from tightly packed formations be them in the sky, or approaching from front and then fend off any melee attacks.
>Countering the diamond dogs would be tricky, but manageable.
>The New Model Army also needed officers.
>Preferably non-noble officers.
>Preferably non-noble officers who would be fanatically loyal to you, or at least Equestria, over Celestia.
>You, Shining, and Twilight worked together to create a comprehensive officer's test and even setup a new officer's academy open to everypony, solely on the basis of merit.
>Existing officers were given an abridged test and assigned accordingly.
>Even the enlisted men would be given the test.
>Seemingly obvious things such as removing the ability to purchase commissions, or removing the requirement that individual noble households contribute troops, were also wrapped up in your orders.
>Overall the first day's planning council had gone well, and you had a definite plan that could be followed through.

>Best of all the nobility would surely be infuriated, but that's fine.
>Celestia would support you not only because she cares about Equestria, but the big scary new threatening Lord Protector Anonymous could be blamed for any excesses while she reaps the benefits of sidelining the nobility.
>Politics and war can never really be divorced.
>The nobility would be a never ending source of opposition.
>Hopefully they could be weakened a bit immediately by appealing to a risk reward calculation, "either give me some or loose all", type of rationale,
>However any threat to their unearned privileges might as well threaten their physical body.
>Heaven forbid they make an honest living.
>You need more allies.
>Commoners you elevate within the army will come later, but you need to get other political allies too to pressure the nobility.
>Just as the meeting is wrapping up for the day and everypony else is preparing for dinner or home, you grab Twilight.
"Twilight in all of the immediately necessary planning I almost forgot another necessity. For the immediate time I think it would be better if I was given some room to stay in here at the palace and access to a few conference rooms to hold meetings as I saw fit. In the latter vein could you please round up as many leaders of industry, merchants, and guild-masters as possible for a meeting in the next few days to occur in the castle in one of said rooms?"
>Twilight immediately begins processing the command and writing it down and gives out a few orders to other aides.
>Before you know it you are snug in a luxurious suite in the Canterlot Castle, hopefully to the noble's dismay, drifting off to sleep.
>All political power ultimately flows from the ability of a government to maintain the monopoly of violence, or as Mao said more darkly that "all political power flows from the barrel of a gun."
>You don't want to rule Equestria, but you do want to remake it.
>The New Model Army can remake Equestria.

>You arose bright and early.
>Might as well make a good impression and get to work, sleeping in until noon would probably not look too good.
>Annoyingly Celestia's need to raise the sun, and thus be up earlier, makes your work ethic look less impressive.
>You walk into the grand breakfast room to find Celestia already eating.
>You wordlessly grab two muffins, and begin to wordlessly eat.
>If Celestia wants to know something she will ask.
>Given Blueblood acting as Celestia's shadow, he should be here anytime soon.
>Any second now.
>"ANON! These orders you put forth are unacceptable they threaten the..."
>Blueblood...
"Good morning to you to you insufferable cunt, what are you going on about now?"
>"Now listen here I'll have you know that..."
>You just get up and walk away, dealing with Blueblood is too easy and it is too early.