From what I read, there were only 2 types of crossbows in Morrowind. Idk how true it is as I have never played it.
And, there was only one or two examples of one of those crossbows in the game, and I can remember only two NPCs (source for one of the Dwarven Xbows) ever using one against me.
http://www.uesp.net/wiki/Morrowind:Crossbows_and_Bolts
And, talk about slow reloads, every time I tried to use one, I would die before I could get the second shot off.