This. I pretty much didn't focus on the clones, I just kept unloading on the Emperor while interrupting everything I could.

I tried just about every tactic mentioned in this thread. The one that worked for me was to merely focus on the Emperor and keep interrupting whatever he did. T7 fell in the first wave but I didn't need him after that. I screwed up a lot but ended up killing the Emperor with 50% health still left.