^I’ve seen the interview where Mark Hamill talks about that (heavy, two-handed swords). But the minute you watch the duel in ESB that arguement kinda goes out the window. Both Vader and Luke use the sabers single handed at various points in the fight.
But yes, Chinese martial arts (specifically thru Ray Park and his king fu training but also more broadly) definitely had a big influence on the PT choreography whereas the OT is much more classic European and Japanese in look and feel.
Though it’s worth mentioning that accurate broadsword and medieval European fighting looks very little like typical “European” fencing that we see in film (which is largely influenced by Olympic fencing) which is more based on renaissance and later sword styles than earlier medieval “Knights in armor” type fighting which had already largely been lost by then. Historically accurate medieval broadsword fighting is actually pretty wild and brutal if you’ve never seen it.
If I had to pin the OT fights to one style or influence, it would actually be Japanese sword fighting. That’s what it really looks the most like (which makes sense given the heavy influence of jidaigeki films on Lucas and his ideas for the Galaxy Far Far Away).
But, again, these are INFLUENCES. Nothing seen on screen really “accurately” portrays any sword fighting style or technique.