Solo Rancor advice

I solo it With Zader (L), Tie Pilot, Palp, Sidious and Rex. P1 is the hardest phase after that it's pretty easy unless you get a really bad RNG. I notice you don't have Sidious but he is an easy one to get and not terrible to gear. Of the toons you have Tarkin might be a suitable replacement for Rex (Rex cleanse is nice but if your running TM most neg status go before you get attacked) to be honest the rancors are lucky to get an attack off. It's easy to get a lot of speed into Tie and Sidious. Sid works really well under a Zader lead he adds damage over time and has an AOE to try and take TM from all the piggies on P1.

I'm just going off what works for me, not saying it's the best solution.