Well, I don’t know much about the ANH choreography but for ESB (and subsequently ROTJ) Mark Hamill studied Kendo (Japanese fencing) and Bob Anderson coordinated the fights in addition to donning the Vader suit for much of the lightsaber fight sequences. Anderson was an Olympic fencer before becoming a Hollywood sword and fight choreographer.
For the prequels Ray Park (Darth Maul) is trained in Northern Shaolin and (primarily) Wushu Kung Fu. He competed at the international level before his film career.
The choreographer for the prequels was Nick Gillard who started as a circus performer before transitioning to a very long and successful film stunt career. A quick and completely UNcomprehensive google search doesn’t reveal any formal martial arts or sword combat training, which when coupled with his circus background might explain some of the common complaints about the prequel choreography (baton twirling…).
I’ve never really looked into who worked on the sequel trilogy fights, although I always really enjoyed the fight between Kylo Ren and Rey in the snow in TFA. The fights in TLJ and TRoS are vastly inferior choreography in comparison.
FWIW I took Olympic style fencing for a few years in college and then spent a decade practicing and competing in Kendo regularly. I also studied a small amount of Iaido and Battojutsu and have a strong general interest in sword combat and general medieval combat (european and Asian). IMO the ANH fight between Vader and Kenobi is the most “realistic” sword fight in the whole franchise, the ESB duel is the best stage combat that’s realistic “enough” and is terribly fun to watch, and the Snow fight between Rey and Kylo really does a great job conveying the sheer intensity of sword fighting to the audience while also being very entertaining. The prequel fights are mostly preposterous and cringe inducing. And finally, NONE of it is even remotely ACTUALLY realistic when compared with actual sword combat. It’s make believe space wizards with laser swords. And that’s ok!