Nice sketch by your brother, oscarreeve.

I'm not saying you should, but you could also add another faction: Archenland. Located south of Narnia between the mountain range which formed the border between the two kingdoms (can't remember its name off-hand) and the Great Desert, they were Narnia's longtime ally.

They were mostly human, and would have more of the typical unit roster of medieval Western Europe: your standard cavalry, archers, etc. In fact, you might even want to consider replacing the Telmarines with the Archenlanders, as that would make a little more sense, continuity-wise.