The swordplay in that fight isn’t good, but they were still figuring out how to do the lightsabers. GL tried using glowing rods (with wires running to wall sockets nearby) to create an in-camera effect that wouldn’t require post-production rotoscoping. It didn’t really work, so on later films they just used colored sticks which gave the actors much more freedom of movement.

I will say I’m amazed that aside from fixing rotoscoping errors, GL hasn’t put some sort of messy CGI in this bit of the film, since so many people (even on this very site!) complain about it.