As an archer myself, i feel like HA are getting better and better, after always playing.
It's true a "normal" HA is just bothering, but a good HA is kind of OP. His only counter are ranged, and when he's good, he just knows how to dodge them. And i would even only put archers in their real counter, since after a xbow shot, he won't be allowed to reload quietly when an HA is near.
The thing wich bothers me, is that good HA are the only "class" wich is near to unstoppable. I can deal just fine with good 2handers, good Shielders, good footranged, good 1h cav. Good lance cav are already starting to be a pain, but i can stick to my pikeman friends, or go on a high place. Good HA are just a BIG pain.
What i also dislike, is that foot PD5 archer doesn't have any advantage in terms of bow/reload speed/accuracy, versus an HA. If you want to be a 5 PD foot archer, then you take all the inconvenients of not having 6 PD, and the no-maneuver. Foot archer got 7 athletics or such, some times 3 PS. Put 5 points in riding skill, 5 points in horse archery, and you'll be way more deadly as an ha with the same "dedicated" build. It really feels like if you have the money, you ought to go HA, and that's, imo, a problem.
Suggestions :
Add a 5PD bow not usable on horseback, with slighter better stats than the actual strongbow.
OR Make the strongbow not usable on horseback AND add a 5PD bow with slighter worst stats than the strongbow, for HA.
And you will also add to diversity this way. :S
Please note though, that if the horses (especially the arabian one) get a slighty nerf in terms of maneuver and speed (with a boost of hp or not) it will also be easier to deal with. Though HA will always remain the ONLY class with no melee counters.