One headshot to an armored horse isn't enough to take it down. I headshot a courser and it still needs another arrow before coming down.
And yes, i use a MW strong bow and bodkin arrows.
Actually, the best gameplay to kill horses is definitely xbows. Since one xbow headshot can kill pretty much anything, and even a normal shot will still take 70% of the health of the horse. I'm afraid sometimes cavs don't do the difference between incoming bolts or arrows. Can't blame them, the range thing disapear sometimes after the impact, so no way to notice it.
The thing is, saying 3 arrows are enough for a horse is definitely true most of the times, but one lance thrust is also enough for all archers. Do you think an archer has enough time to shoot 3 arrows on a horse before the cav comes and kill it ? Seriously ? And... we can't shoot arrows AND block down. As an archer, i must pass at least 20% of my short lifespan using a melee weapon just to down block, doing nothing else. And once you see an archer using a melee weapon, just run in bumpslash or couch. :S
And.... horses and cav are not EASY to shoot down at medium distance. This is just an asumption because when 4 archers focus you, one hits.
"Ah, i got hit by thoses filthy my old friends medium distance, nerf range !". But that's 20%.
Kerrigan is definitely the deadliest i encountered. Evading arrows pretty easily, insane speed on that courser, and if you shoot the horse, running at you with a GLA to chop your head off. o_O
You already did Riddaren xD If i'm not mistaken.
Oh, and for all :
Difference between a strongbow foot archer and a strong bow HA ? : Riding and Horse archery (8)
Difference between a polearm cav and a polearm footman ? Riding only.