What about making the CO for missions be either Aziz or Kerry, and considering the death of either in the mission to invalidate the mission result. This would make gung-hoing the CO role less viable (if you care for continuation, that is) and would mean that complete and utter routs would have an added objective of "keeping aziz/kerry alive at all costs and get out" (or, "shoot the CO" if you are a gamey bastard....

So it would make it a bit less fun for COs that like to gung-ho stuff, and it would be a bit finicky, but would give every mission an extra objective. (And besides, failure only means an opportunity to try again later, right.) Also, we would risk having the wind go out of players sails as they know that the mission will not be a success-success if the CO dies and they press on.
Anybody care to comment on that?