Considering a Tarkin Lead Arena team - need help!

So definite characters would be:

- Thrawn
- Tarkin
- Shoretrooper
- Nihlus

Then I have a tank, a displer, TM reduction and cleanser (albeit not a team wide one).

And its a throw up between Thrawn or Tarkin lead - one of which I could Zeta.

Would people say that ideally the 5th character should be Death Trooper, but until I have him, TFP would work well due to the Debufs Tarkin can inflict (to increase his damage an TM)