I voted no, for the sake of variety. Leave them in, more classes spice up the gameplay.
Instead do the following (I can't believe I am suggesting a nerf):
- Make bows and crossbows unable to be used from horseback
- Copy all bow and crossbow items, remove the "unable to use from horseback"-flag of those new weapons again, add a "cavalry" in front of them and make them require both PD and HA. Since it's new weapons you can make them have different stats compared to those which the foot archers use.
- Remove any aiming bonus HA is giving
The result: we changed the playstyle of the class. Since moving while shooting won't let them hit the broad side of a barn they need to play more like "Dragoons" or "Mounted Archers", which means they more or less can use their horse only to position themselves or to escape, but must remain stationary to shoot.
Advantage: much easier to be caught by enemy ranged and cavalry
Disadvantage: no change towards infantry