The priest needs to be Holy/Disc, drop the shadow.

The warlocks need to be Affliction, so you can be mobile non stop while using the "fire and forget" method.

3 dots from each Warlockx4 = 12 dots in roughly 3.5 - 4 seconds if your good. As well you have 5 instant cast aoe fears for anyone that gets up close and personal.

Overall your guaranteed with this method to kill anyone in 4 seconds of cast time and just let them run around. As well the dots can be cast while running and you don't need to be facing the target.