Femboy Fantasy Tit Tacs

I really thought slamming my way through Tactics Ogre would prep me for this. I'm only like eight hours in and already I have underlevelled characters I can't do anything with. I haven't even started messing with classes yet, please help. Save me, training battles.

Also why team size so small

EDIT: Why are black mages evil. Ranged lockon fire attack that kills you.

EDIT2: the best strat for black mages is kamakaze basically. They have a lot of range and can snap to targets freely, so running next to another enemy will result in their multi target fire killing one of their boys.