Easy fix in order to nerf but not gimp the team is to have Traya gain enough TM under topple while a player character gets a turn so as to make it possible to do say a 3-5 million damage run. Mechanics change could read something like:
While Traya is toppled, she gains % turn meter every time an enemy takes a turn. This turn meter gain cannot be prevented.
They could do the same with the tank raid but to such a degree that it wouldn't affect other teams like JTR, although I prefer for there to be the possibility of auto-ing the tank raid as at this point it's more of a chore than anything else. Plus the ZFinn team there should be proportional to the AAT raid's difficulty in relation to the current game power creep (requires CLS, Han, BB8, and C-3PO, which all take a good chunk of time an effor to acquire).
Furthermore, if the spirit of the game is also to aim to reduce the amount of time players spend in-game as was mentioned in a post many months ago, it makes sense for them not to nerf the team for the tank raid, but to nerf it Sith Raid to require enough investment in the player's roster so as to not make a whole phase trivial.