Ooh, interesting idea! And I happen to own it.
I could remove all the ROTS audio and replace entirely with that audio, so the music wouldn’t be a problem, and the sword noises might sound funny in a lightsaber fight. The only issue I see is the dialogue, which works great, but there’s nowhere to put it - i.e. there’s no dialogue in the SW fight so no lip sync to use.
Maybe at this point they can both just be thinking at each other?
You could just drop the dialogue in a scene where you can’t see their faces well enough to see if they’re actually talking.