Did bullwark yesterday (I'm a Sorc healer). My trick after the first wipe was to get everyone in close, and the stick a healing circle underneath him so it would be reachable for everyone.
The tank was with his back to the energy shield (Bullwark facing the shield). The shield I mean is the one that opens up after he's dead, not the bubble around him.
It was tight but doable, make sure DPS'ers get into the heal circle, and use stimpacks when they can.
We ignored the droids to beat the enrage, I just CC'ed the ones that were trying to kill me due to healing aggro (when I could), I tanked them the rest of the time.