Woops, I missed that there was a thread on this topic already.

Give mages another protection spell that's generic to all the wand users. It can be something like 30% damage reduction to all forms of damage and it can have a reuse timer that's twice the duration of the spell, so it can't be kept up 24/7.

All of the other wands would be reduced in effectiveness. Combining ABS + this new spell would have the same total damage
reduction as ABS currently has.

Like the other idea, this helps to fix the competitiveness problem some mages have.