I would just like to state that I LIKE the limited control. The idea with "Cast specific spell" would be cool. though, as would a "attack mages", which would target the nearest character that had cast a spell.
Attack leaders, however, would be extremely uncool.
All this is in thread with my "Micromanagement is bad theme".
(If I had my way, you would not be able to build armies except at your capital. At all
That would also make light infantry more useful.)