[Teleolurian]

By the time you have a staff of storms, you won't be relying so heavily on longbows anyways - your initial expansion will probably be over by then. A small group set to guard commander might be able to sneak attack a province - Thunder Ward, Wrathful Skies, beat feet out of there. OTOH, man's mages only come from the capital, so they're rather at a premium (i.e. you probably won't want to try this with them).