Tier 2 can be done with a level 50 Chewie properly geared, and Royal Guard and Stormtrooper at 40 and moderately geared.
Get through the first two rounds focusing fire on the AoE attackers.
Third round goes as follows:
- Ignore the droids.
- Everyone gets at least one free shot on Mace. Be sure that Chewie's taunt is up before Mace gets a turn.
- Mace attacks Chewie, puts Shatterpoint up.
- Everyone keep attacking. On Chewie's first turn, use his defense boost / heal, which removes Shatterpoint.
- At level 40 your guys should be able to withstand a regular hit from Mace. If he hits the trooper next, use his defense ability to remove it. If he hits Chewie again or the guard, use the guard's ability.
- Keep focusing him down.
This works roughly 80-90% of the time with those levels and gets easier as you level Chewie up.
PS In my previous post I meant Boba Fett, not Sidious. Boba makes this trivial.