It's very possible you need to use your toolkit as effectively as you can all while being ahead of the DPS/Heals on threat. For bosses you see DPS using offensive CDs at the start Fight or Flight should be used I find from personal experience Toto-Rak is the only place that is crappy. Not only do DPS get their 3rd combos but they start getting maim+ mend (dmg/auto attack dmg) and stronger abilities to amplify their threat. If you're on point with cycling your emnity combos and using Flash as much as you can to fill in you should be good.