Put Sabine in a catapult and toss her into the sun. Use Chopper.
Turn basic only on in the autobattle options and auto through the first three sections, turn it off for section four. Use Chopper or Ezra to remove the Stormtrooper's taunt, kill the deathtroopers, finish off the Stormtrooper, kill the Commanders, take down Thrawn.
Kanan taunts immediately to eat the Fracture. Hera uses Backup Plan on him. Otherwise just keep using his basic attack and Total Defense on anyone that's low on health/protection. Taunt when you're pretty sure Fracture is coming off cooldown (it's easy to lose track).
Hera throws Backup Plan on anyone that's low on health, which is usually Chopper or Kanan. Keep calling Ezra to assist with her other special any time its off cooldown.
Ezra attacks whoever the current focus target is, save Flourish for when the Stormtrooper taunts. Call Zeb with your assists if you're targeting Thrawn to put Daze on him, otherwise call Hera or Chopper (for more buffs).
Zeb hits the target with his heaviest available attack. Save Honor Guard for when someone is low on health, which, again, will usually be Chopper or Kanan.
Chopper taunts whenever possible and uses its cleanse whenever possible--save it for the Stormtrooper if they're still alive. Its basic is low damage, but you'll get a lot of them off if you've omega'd Chopper's unique and that more than makes up for the low damage.