Trust me, if you take away light crossbow the ability to reload on horseback, when they start to use arbalest, shoot then stop, dismount reload then mount himself up again then shoot, that is even worse as it will only slow down the round even more if they are the last one alive
Edit: also they are only good on open maps, on village/ city/ siege maps their efficiency is extremely low, especially on maps like nord town/ riot of swadia, they will probably just going to leech on those maps since they are useless already enough