inf melee - high damage output, high hit rate, high risk
ground ranged - slightly lower damage output, much lower hit rate, low risk
melee horse - high damage out put, lower hit rate than inf melee but higher than ground ranged, medium risk
horse ranged - lowest damage output, lower hit rate than ground ranged, lowest risk
Think about it, 1 horse archer can fuck up a cavalry ARMY, purely because they can't catch you and you can snipe their horses out with impunity. You can ride around melee guys, bumping anyone with a shield. Oh what's that your eastern warhorse isn't tanky? I call bullshit, you're just riding into projectiles instead of away from them. Destriers are tanky enough against range if you don't run at them head first. I really doubt you do THAT much less damage now Pp, considering what mechanic changes actually happened (foot archery still deals damage fine). So you can't shoot plate horses and infantry to death quite so fast anymore? GOOD, when I'm playing as my archer I'm not going to target B0nk or Butan or Squall or Falcom or Friedturtle or Bobby or BillyBaddAss cos I know I'll be inneffectual against them, this doesn't make me useless as you seem to profess, I shoot other ranged but ok I get you're too scared to do that. So shoot the support guys, shoot the long spear users in mail, shoot the 2h kuyak my old friends, shoot panos, shoot anyone up to coat of plates if you've bodkins or up to brigandine with cut arrows. You shouldn't expect to be dropping the enemy heavy hitters like flies, pick off the slightly weaker guys, then when melee hits, instead of 2 vs 2 with the enemy tank at 2/3 health, it'll be 2 vs 1 against the tank, greatly improving the odds.
You add Bubba have said your class is oppurtunistic etc etc etc, but you can't see how simple that is? Leave targetting the heavies to xbows and longbows and melee, disrupt the lighter infantry, and hell when you say you can only hurt guys in light gear, that's still up to around the 12k mark. Bump in melee a bit more, get involved, pick up a couch lance when you're ineffective against the enemy armour and aim the tip at their head, adapt in a way that makes you useful, stop trying to adapt in a way that you can still hurt heavies.