Got halfway through the thread and got bored but here's my take on the situation.
When you're combining the mobility of a horse with the range and fire rate of an archer you're always going to have issues. Horse crossbowmen are a similar issue but because their reloading takes a lot longer you can escape to cover much easier whereas a horse archer can continue to pursue you forever. The smaller bows dont hurt so much but the yumi especially hurts a lot, I get 2 shot by it in a kaftan and 3 shot in my +3 leather over mail which is comparible to rus or long bow damage and even heavy crossbow. This wouldn't be so much of a problem if they didn't shoot so much which is solved by either reducing ammo counts for quivers which I think is the best choice or lowering the fire rate which wouldn't change all that much.
I think lowering the ammo available to archers would solve many issues in the game right now. Horse archers wouldn't be as effective for obvious reasons buy I think it's a suitable need for foot archers too, having to pick shots better rather than peppering you relentlessly with the smaller bows, it would also nerf kiting because eventually archers would need to salvage ammo bringing them closer to the fight.
Especially when you consider ammo counts were buffed when we had 150+ players on and now we're getting half that or less, the individual arrow becomes less valuable.
Crossbows have their reloading time, melee have block mistakes, cavalry have dehorsing, archers need something too and I think less ammo is the right option.