This is the last thing that does bug me a bit. Here’s my suggestion… Save the end of Obi-Wan & Anakin’s fight from “AotC” for the end of the final fight between Obi-Wan & Vader in Episode 6.
I did something similar to this for my edit and it REALLY works, although I moved the Obi-Wan and Vader fight into the bacta tank. Can see it here.
https://vimeo.com/723720916