Brilliant analysis! Never played Ogre Kingdom, but I can see that a tyrant is quit a match in CC.. I suggest a rain of fire from both shooting and magic. Don't bother going for heavy spells like pit of shades. Remember, you uses a lot of dices on a spell that most likely dont do a damn thing.. I would go for lots of magic missiles and maybe death lore for steal soul to slowly pick him apart. Then I would take 3-4 units of 10 skinks each with blowpipe and some sallys. Finaly I would go defensive a try to get a combined charge on that tyrant, maybe from some swarms(to hold him-and possibly do a wound) and a heavy hitter like kroxs or a scar-vet.