[Edi]

Those English longbowmen were trained to the bow from since they were little kids and the kind of damage and deformation we're talking about came about through a lifetime of such stress on the body.

People who are trained as the kind of archers we're talking about here would be able to fire the amount of arrows as specified in Dom3 as bow ammo would not get appreciably tired compared to people swinging swords and bashing each other about in melee, so the 0 fatigue approximation for shooting sounds right to me.