Personally, I'd play from the druid and have your locks just back you up with DPS and off-tank. I have my "[" key set to nothing more than a "/petattack" macro. This means I can target off-tank targets, hit that key and then focus on my main DPS target while the voids off-tank everything else.

Playing your main as the one member that controls the situations is, IMO, the best option. For a druid especially as it will be the character that tanks, heals and CCs most of the time. Besides, you can collapse warlock abilities down to a LOT fewer key combinations than you can all the druid spells/shifts/CCs/heals/etc.