well square formation does work very well vs horse archers. A.I. is only ok at best using terrain to mess up horses. it DOES do it. but not nearly as well as a human does.
he didnt scroll down, so Im not sure what exactly the enemy was fielding. But, this is also his elite companions vs regular units, even if they were his upgraded t5, they'd still be well understated vs compaions pushing 200+. possibly running 3 quivers.
A.I also breaks its morale too easy. so, often gets routed super fast from that.
So the A.I, will usually square formation up vs horse archers. But, then not have a proper full cadre of units, so not really match the player 1:1. other units, without sheilds, or bows to fire right back, will get routed and break. the archers who unless are equally tiered, (aka, fians) will not be able to lead and match the horse archers 1:1, and also break eventually.
battanian fians in a square formation will massacre horse archers for example.
I think better units need to be more expensive. sure horse archers are already with mount/warmount costs, but I think it needs to be even larger. So its not 50 palatine guards vs 50 horse archers. its 100 palatine guards vs 50 horse archers.
There are of course further mods that address some of the problems. "armor does something", or "realistic battles"
Atm, there are 3 damage types. cutting, blunt and piercing. arrows, sword thrusts, pole thrusts, and lances/pikes are peircing. sword/axe/polearm swings are cutting. maces, rocks blunt.
all cutting does bonus damage to stuctures,shields. armor greatly reduces cutting.
all piercing does reduced damage to structures/shields. bypasses armor.
blunt is just 1:1 I think.
So, obviously theres a problem here. arrows, sword thrusts are treated the same as javalins, pila, and lances... the game doesnt care about heft, or weight.
So, arrows pierce right through armor like nothing. and pila, spears which are designed to pierce shields... are stopped dead by them.
"armor does something" simply swaps arrows to "cutting damage". this makes it so armor greatly reduces their damage. nerfing archers quite a bit. however, it has the problem of making arrows/ballista wreck seige weapons/barricades.
"realistic battles" is one Im considering trying.
it more directly modifies arrow damage from what I understand to be more physics based, and not use the bows listed stats.
it also, makes troops raise their shields in all formations. And modifies shield hit detection to be more visually correct. which actually leaves more gaps.