cRPG combat is slow enough without stamina. And as GTX said, it would just add more limits to melee combat, which we dont need in cRPG. The main attraction to Warband/cRPG was how fluid the combat felt (before this patch), a stamina bar would just make it clunkier then it already is.
to the original topic, different damage for the hilt/blade sounds great, just hope that the damage for the hilt isnt so low it will constantly be glancing.