In my experience with mages, they are very auto attack centric. You need to shoot a lot with double wands from a distance to shred the magic armour to a point where you can nuke it in one blow and apply conditions.
Then I suggest that you're using your mages wrong. That is only correct in the early game, up until maybe level 5 or 6.
Once you get a certain number of skills, and enemy armor increases to the point where it's not easily taken out in two turns, it starts becoming more efficient to use your powerful skills, knowing that they'll be back off of cooldown by the time the armor is gone. You'll get the armor down much faster, and be more effective by using skills than without.
