Just recently unlocked Jabba; no Ultimate, yet. My Hutt Cartel are still lacking a bit; I use both Tanks with Leia.
Took many attempts; leaving the healer for last seemed to work best for me for first round.
The first round seems to be the Hard one. At least 1 of my guys die, sometimes 2. Thankfully, they Come Back in the next round.
And, the Contracts usually activate near end of Round 1 or beginning of Round 2; becomes smooth sailing with the Contracts.
Did find it a tad disheartening that it's not Simmable, but fairly decent Mod upgrade material rewards.