I've run a vader, defender firespray list before and it did quite well. Squad leader on vader, naked bounty hunter and vessery with VI.
Worked really well. Vader stays relatively close and hands off actions to modify the firesprays shots. Vader himself target locks on vessery's intended target, this means both your defender and firespray get consistent tl+focus attacks.
Without fail, vader is targeted last - and a late-game vader is the best vader.
Give it a shot. Not sure how you could jam a phantom in there tho. Not sure id want to try. Vader and phantom occupy too-similar a role, your defender would be the only anvil and would be focus fired down pretty fast i would think , leaving you with two flankers - one squishy and the other toothless.