My group is 3 healing this fight on normal and we're running into problems on the second last head. We pop hero, but there is just too much aoe damage going out. We've been doing the G,R,G,R etc. Our dps is dropping because they're always trying to help the healers. Is there a berserk timer on the fight? If not, would 4 healing help? We have tried throwing in blue heads, but everyone seems to prefer the other method.