I'm thinking of a "circle-casting" style trait for trained mages that would amplify the effect of their cast spells (not staff blasts, as that's inherintly boosted by larger formations, of course) based on the current size of their formation. So a 6-mage group could cast stronger spells than a 5-mage group, and so on.

I can't think of any existing examples of such functionality... Anyone already invented this wheel, by chance? Or at least ruled it out given current tech?