And what's the reason to guard the healer if you can easily keep the mob? he will not get a lot of dmg as no mobs attack him
unavoidable damage? Damage that is raid wide. however I would say it is more depended on the groups gear. If healers are both well geared, put the guard on the mdps that stays in for lightining phase and any other dps/healer that seems to be taking excessive damage.