The tanks job is not to worry about damage thats what the DDS are for. I shield lob wait till the mobs are all close to me trigger flash. I do one or 2 combos on a mob then shift to another target and pop a combo or 2 on them. Dont hesitate to throw a shield lob in. The parties I have had have been up to 30 (beta phase 3). It also helps if the mages can sleep some of the extra targets. Oh and by the way that sign over the mobs crap is for the birds. SOP is to attack what the tank is attacking, and youll tell by the hp decrease. I dont mark my targets you should see what im hitting and whack it till its dead..then go to what im hitting. A good tank (such as myself) will realize hey in .05 seconds this mob will die so ill switch to the next target to get a ws in to help lock hate. Thats how its been done since the first umbral era and thats how it should be done today.