Combat casting seems to me to be a wasted Feat for this NPC. It should be replaced with either a combat Feat, or a general Feat that is is more likely to come into play. I would suggest 'Improved Bull Rush', 'Improved Overrun', or 'Diehard' as combat-related Feats. 'Lightning Reflexes' to boost that poor reflex save wouldn't hurt, and 'Stealthy' or 'Diehard' would make this "Chieftan" much more likely to survive an encounter with a hostile group of PC's (and thus more likely to be a true "NPC", rather than just another part of an encounter).