I can't use the team in question, but I don't think Finn should be messed with at all. He and his zeta were around long before the Sith Raid and is useful throughout the game in other modes.
Changing how C-3PO's kit and how it interacts with the raid is a better change since he is new and you can claim bug-fixes.Just my thoughts. If you change something with Traya, it might interfere with other existing strategies that work.
Synopsis: Don't change something that was working well within the limits of the game because something new came and broke it. Fix the new thing so that it works within the limits of what you want the Raid to be.