Have you tried this with Grievous over 50% health? Ahsoka's special would heal for more and might be able to keep QGJ alive longer. Not sure if that would be entirely necessary based on enrage. My guild doesn't do Heroic AAT but I usually get ~900k w/ JKA (L), Ahsoka, IGD, QGJ, and Yoda (Don't have Aayla and need his Tenacity up to stop the DoTs when I can. Plus if he gives Foresight it stops B2 from taking off Offense up/Tenacity Up). After around this time he usually enrages. JKA (L) really adds to the damage output so if you can get your team to survive until enrage the dmg is much higher, but as I said, I don't know how this would fair in Heroic AAT.
I have JKA modded for health and potency and crit chance (Only 6 stars atm so I need that extra health). Ahsoka is crit chance and damage with health primaries on both circle and cross. IGD is crit chance and damage as he's already pretty tanky and hits great against the droids, QGJ is potency and health mainly cuz I don't like switching off all of his potency mods from the rancor raid, and Yoda is tenacity and health so he doesn't get ability blocked too often.
