Of course weapons and weapon skills would have to be balanced, else the warriors would all use the most uber weapon in the game.. and then the game would turn out as diablo 2 (the horror!!)
The same goes for spells, although one of the ways could include the most powerful spells of destruction and another the most powerfull summoning and a third the most powerfull healing without that unbalancing the game.. You would just have different \"classes\" of mages...