Assuming, of course, that Wizards wielding staves instead of dual clubs is a desired outcome, then the staves should have something to compensate for the loss of flexibility dual wielding clubs allows. Maybe in a non-caster direction. Like, say, 4 slots for caster type enhancements (making up for the 2 for each hand) and clickie type slots and/or a defensive type slot. Add an acid guard or fearsome to it.
Just a thought.