A-p's already get excision which is unique to them. Though I understand why they get it I think that giving this to mages would be a little extra mageness, nothing that I forsee changing the entire philosophy of mage combat but nifty. Keep in mind you can also see potions while blind, so when you can't see that other wand, stave, or scroll, you could simply hurl a potion hoping to hit something. I would allow it while blind because well if your close enough to exchange physical blows you still stand a good chance of being able to throw something the few inches or feet to strike them.