Took me ages to realise my bigger armies were losing because half of them weren't even in the fight
this is one of those mechanics i technically knew existed but clearly didnt actually understand, because i kept making the same mistake for way too long.
my assumption was basically more cohorts = more damage = i win. so id stack a big stack, catch a smaller enemy army, and then just... lose, or win but take way more casualties than i had any right to. and id blame the dice or the commander or whatever.
what finally clicked is combat width. the battle is fought on a line and the terrain decides how wide that line is. so if im in narrow terrain with 30 cohorts against 20, we might start with almost the same number actually fighting, because the rest of mine are stuck in reserve doing nothing on day one. they fill in as units drop but theyre not applying my numerical advantage up front. so 30 vs 20 was never 50% more damage, i just assumed it was.
the part that actually changed how i play, if youre the smaller or weaker army you WANT narrow defensible terrain, because it caps how many of the enemys cohorts can engage and stops them surrounding you. and the reverse, if youre the big army dont go attacking someone sat in a mountain province, youre throwing away the one advantage you have.
also learned maneuver is range not damage. i used to crank preferred flank size to max thinking more flanking, but if the units on the flank dont have the maneuver to actually reach anything theyre just standing there looking pretty. the setting gives them space, the maneuver stat decides if they can hit from it. two different things.
and the fort thing got me more than once, if youre besieging a fort and a relief army shows up you count as the attacker, so all the defensive terrain is working against you not for you.
anyway now i actually check the combat width of the province before i commit to a fight. feels obvious typing it out.
whats the worst one youve lost with the bigger army. i want to know im not the only one whos fed a doomstack into a mountain pass and watched it evaporate