I ran it without chopper.
Sabine G11
Ezra G10
Hera G8
Kanan G8
Zeb G8
Sabine and Ezra have good mods (Sabine has almost arena worthy mods) and the other 3 have decent mods: nothing special, but level 15 and 5*.
Make sure you mod your toons with a good amount of protection. Zeb's unique gives them all 15% protection recovery whenever they take turns.
As far as strategy, I recommend dropping Hera's backup plan on Kanan ASAP when you reach Thrawn and then make him taunt. He has decent defense and protection to absorb some hits but he WILL go down and be revived. I used Ezra to remove the stormtrooper taunt and then went after the deathtroopers first. Sabine was fractured first (probably because she is the fastest) so she was largely a non factor. Use Zebs sweep attack to knock out the special buff on a DT and potentially Sabine's AOE to hit the other. Try to use the assists on Hera and Ezra to call your damage dealers and take out the DT quickly. Ignore Thrawn until everyone else is dead. Use armor shred on him to make him go down faster and protection regain abilities plus backup plan to keep your guys alive because Thrawn still hits hard.
Hope this helps in some way.