The two guys with swords just stay down there and stand on the totem and the totem never goes off. All they have to do is stay alive and kill the knights basically. The other 4 members just stand close to the middle plate with the auras and switch off, that way they are right next to it. it leaves 4 people constantly in the middle to kill the ads. I did it yesterday for the first time because I never did it before, it was pretty easy, only problem was I started to run out of ammo being on the plate. I just had them let some thrall through and I melee'd them to get ammo. Not a needed cheese, but did make it easier. People in the middle still died though.