When i lvled thm I just used to ask if I should sleep and single target, single target and ingnore other mobs, or just AOE always depends on playstyle of the group. Sleep can be a pretty pain if ur lazy-tank doesnt flash sleeping mobs or ppl randomly use AOE, Its just one of those skills I use to talk about before starting into dungeon (If ppl dont rush off like buffless that is). Also on 2nd boss Bray NM it is pretty handy but all a matter of talk to your team