[geo981010]

Hey Argitoth-
Commanders without orders but who have troops with them will default to the stay behind troops orders (or spell/fire if they have that option), so maybe someone didn't assign your two headed friend any orders?

If your C'tis mage attacked them, the archer would fire, the Ettin would stay behind him and not engage, and if the archer dies the Ettin would rout. (if all troops are killed, non-immortal commanders will automatically flee even if they should be able to win).

If the Ettin is alone, even without orders he will attack, so you have to be careful to set him to attack something in the orders screen...