Yea trooper is great!! He dodges all the dispells and even if he does get dispelled, he can easily regain taunt back!!
I would totally drop Vader and look into Zavage eventually. He makes zaul teams really fun!!
Nihilus in an all sith squad is very important because of his dispell. Also if you do have Nihilus you could potentially drop ep to pick up a stronger sith that doesn't rely on rng.
Right now I run zaul/Zavage/zooku/ep/gk
Going for zaul/Zavage/zooku/Nihilus/trooper
Gk is alright in the squad but trooper would be better because he has a higher dodge chance and you can trigger his taunt.
