Having been an xbowman for a while now I decided to try being an archer with a STF char. My conclusions are that if you take the xbows as being balanced vs melee (which I think they are) then the high end bows are definitely a little underpowered in terms of missile speed but they are too accurate. I think the bow difficulties are also off compared to their damage, since to me difficulty is a direct measure of the bow's poundage and damage should therefore be proportional to difficulty.
I don't think it would take much to bring them into line though.
The first thing that needs to happen is that they ALL need to do piercing damage. It just makes sense.
Next I would change the bow stats to the following;
Short Bow: Difficulty = 1, Missile Speed = 35, Damage = 13p, Speed Rating = 75, Accuracy 99
Bow: Difficulty = 3, Missile Speed = 39, Damage = 19p, Speed Rating = 65, Accuracy 97
Nomad Bow: Difficulty = 3, Missile Speed = 39, Damage = 19p, Speed Rating = 65, Accuracy 97
Yumi: Difficulty = 4, Missile Speed = 41, Damage = 22p, Speed Rating = 60, Accuracy 96
Tatar Bow: Difficulty = 4, Missile Speed = 41, Damage = 22p, Speed Rating = 60, Accuracy 96
Rus Bow: Difficulty = 5, Missile Speed = 43, Damage = 25p, Speed Rating = 55, Accuracy 95
Horn Bow: Difficulty = 5, Missile Speed = 43, Damage = 25p, Speed Rating = 55, Accuracy 95
Long Bow: Difficulty = 6, Missile Speed = 45, Damage = 28p, Speed Rating = 50, Accuracy 94
As you can see overall bows get a slight damage buff and a decent missile speed buff, but this is compensated for by a nerf to accuracy.
The bows are now also pared up giving people a choice of models at each PD level which is good as it means everybody doesn't go through the recurved bows which aren't very European and therefore don't fit with some character themes. Ideally, I'd rename the Long bow as "Heavy Long Bow" and then stick a PD 4 Long Bow in there to give an alternativ to the Yumi since the Yumi model is not European either, but for now the Yumi will do.
The final thing I would do is make the Crossbow, Heavy Crossbow and Arbalast have difficulties based on wpf. 20, 40 and 60 should be fine for each respectively. The only aim here is to stop any old person picking up a crossbow and being able to use it. Whilst I believe Xbows are balanced there are still too many of them. I'm tired of seeing them being used by everybody especially in Strat Sieges where melee chars use up all the bolts, decreasing the effectiveness to dedicated xbowmen. It might not be realistic, but its definitely more balanced.