Well, I don't really know what stats are increased with WAR as support, but at THF LVL30 you can use WAR LVL15's Berserk ability, with boosts your attack but lowers your defense. Not a problem since you won't be getting attacked anyway
You can also use the Taunt ability as a last minute emergency if the other tanks can't take aggro off the mages, but it usually fails.(at least in my experience)