Ironically, Maul works well with QGJ... If Maul gets called in early in the battle by QGJ's Harmonious blow, he gets a +75% damage bonus from QGJ and possibly a +100% damage bonus vs Jedi. This is most often an insta-kill of any Jedi in the game including Barriss. I usually target Luminara.
Having killed one Jedi, Maul immediately gets to act again, buffed by Crit up and possibly ATK up too. He'll crit about 80-85% of the time. If there are any other Jedi in the enemy form you will have a good chance to take them out in one shot. Otherwise, just pop Maul's AOE.
All this potentially right from the beginning of the battle, with QGJ being one of the faster toons around.
Maul, just like Ventress, works great in a Phasma team too btw.