In another part of my life, I’ve been practicing a sport called historical European martial arts (or HEMA) for the last thirteen years–in other words, practicing, coaching, and teaching swordfighting from historical manuals. While I would not characterize myself as a Miyamoto Musashi or Inigo Montoya (unless they were a short, chubby, easily-winded Musashi or Montoya), I think at this point I have a decent grasp of the practicalities of fighting with a sword. And I think writing a swordfighting scene well is a lot like stage choreography–you have to strike a balance between what is entertaining and what is ‘truthful.’ (I use the word truthful here loosely, as I’ve never been in a ‘real’ swordfight, but I have read many period accounts and have my own extrapolations based on studying period sources.)
Another consideration, of course, is not drowning your reader in too much technical detail. I could very truthfully write Julia constrained his blade, then advanced into the stretta and struck him from prima, and that would mean literally nothing to your average fantasy ready. Better still to write Julia caught his cut on her blade, gliding the point in to thrust him beneath the chin. I think the latter paints a better picture, and that’s what writing is all about–painting a good picture for the reader to lose themselves in.