Lol, the Onion Knight not leading the archers into melee rather just standing behind the battle line to turn anyone flanking into a pin cushion would have prevented it.
That's accounted for in the show though. Ramsay didn't unleash the phalanx until after he saw Davos commit the last of the Stark reserves. Plus in the case of Davos, he's always said he's got no real military experience. He's a former smuggler.
Which segues into another point.. Ramsay was hardly a military genius, himself. Any fool can win a battle when your army is twice the size of your opponent. Yeah Ramsay had his moment in goading a Stark to act like a Stark, but had Jon fought like a cunning commander rather than a Stark he actually could have won the day even without being bailed out by Littlefinger. Ramsay committed his entire force to crush an outmatched force. Had Jon just sent a small flanking force, say a Direwolf or a dozen or so wildling irregulars, they would have caught Ramsay utterly alone (save those two useless heralds). And how did the Knights of the Vale even arrive by surprise? We
just had it established that House Glover reestablished control of Moat Cailin and that they were choosing to remain loyal to Ramsay rather than rebel against him. So how did the Littlefinger's army even get up through the Neck without any alarm being raised? The only answer I see is that they did force their way up (House Glover might not have sided with Jon, but they clearly didn't love Ramsay enough to try to truly stop an invading southern army either), and Ramsay simply didn't do his due dilligence in reviewing intel reports. How else can he not know a foreign army is moving up from the south?
So, incompetent commanders on both sides... only one army was twice the size of the other so it's no surprise that in absence of outside help, the smaller side just gets crushed.
Some of my own ideas on how to reskin the battle for the BTU:
The phalanxes: They're inexorable and inevitable death from beyond your reach. That screams artillery. Maybe even ortillery :)
The archers: Conventional and Aerospace fighters. Makes extra sense that the artillery comes into play once the opposing air is no longer available to respond.
Wun Wun the Giant: A superheavy mech. Mabe an Ares series if the battle is in the Dark Age, but I prefer some industrial superheavy kitted out for war. Like a 300 ton agromech described in MW 1st ed, or perhaps something more contemporary like a
Kiso. Need an obstacle to come down? No problem!
The Cavalry: Obviously the mech forces. First into battle, focus on each other, and (one can assume) they have most of the glory and prestige going into the battle.
The Footsoldiers: If the cavlary are the mechs, then your men at arms and wildlings that make up the bulk of your numbers are the conventional forces: tanks and infantry (and BA, depending on era)