TLDR version: HA is fing high risk you pillock.
Best TLDR version ever
To add my input. I have played most horse classes and also a lot of melee classes (by no means do I claim to be good at any of these). HA do minimal damage as it is, assuming they hit their target. Not many horse archers can fire well off horseback at full speed and so you will notice the HA / HX slow down to a walking pace to fire. This exposes them to lancers / other ranged (they stick out). All this to maybe do 1/3 of damage to an unarmoured peasant. Lets not also forget the horrendous upkeep for a HA, arrows, horse, bow.
Now I will list the classes I have played that when played well counter ha.
- Hoplite : seriously just hold that huscarl shield high and watch them try to get round you
- Any ranged : even a normal xbow unloomed is pretty devastating to an arabian (a common eu1 ha horse)
- Lancer : stupid lancers just charge after a ha chasing them for eternity. This rarely works and you end up with a dead horse. Keep your distance, take your moment and go for a single strike. If you miss, just run off towards your own team and retry later.
- any teamplayer : stick a pike being a shield and get that shield to know where you want protection from. No ha is gonna waste their time on that
This argument seems all very pointless anyway because if NA1 is anything like Eu1, very few maps allow HA to play at its full potential as an open field map appears ever full moon atm