Mmmm...
So, in your opinion, is it natural for a rider to stab someone when his horse is jumping? I.. think... the rider must be very skillfull to keep himself hold on a jumping horse and in the same time having enough strenght to hit an armored soldier using a 1h spear, and kill him of course.
I mean... well maybe i have a different point of view on this, i don't know.
I also agree about what FrisianDude said before. Of course when we talk about an OP faction, we talk about weapons and armors. Anything else is about how good a player is.