What Jinko said, it's crazy important that you maintain that proper position. Also that, assuming you don't class stack THMs, you heal melee DDs, don't push it all on the WHMs, let them heal you while you get melees it'll help your enmity generation a ton, which in turn will allow your DDs to go a full tilt more of the time, if nothing else it'll speed things up.

I've also found that if you can get one WHM to focus on melee DD buffs and the other to only heal you and then leave you a small margin to self heal it'll also help keep hate on you and off of your whms. Course if you go all THM it's easy peasy since only you should be getting wailed on.