I cleared it earlier tonight.
https://imgur.com/a/uNj93
Hera, Kanan, Zeb, Ezra, Chopper -- level 72, g7, abilities level 7, all 6*. Arena level mods. You can see the mods on my swgoh profile (https://swgoh.gg/u/indominable%20j/ ) as follows: Hera had Boba's mods; Ezra had Kylo's mods; Zeb had Palp's mods; Kanan had Nihilus mods; Chopper had Rex's mods.
Keys: using backup plan on someone taunting in the last fight -- had a couple of times Kanan came back to life. I dispelled the stormtrooper's taunt, and then focused down the deathtroopers. Next I took out the stormtrooper. I then took out the commando EXCEPT that I used Zeb to keep Thrawn dazed and/or stunned. All assist attacks were used to call Zeb.