Hi Liam, glad to see you on the forum.
It depends on what you mean by "realistic." The re-enactors are getting all sorts of relatively realistic experience about what it is like to move in armor, to fight with group tactics, to deal with different types of medieval weapons, etc. I agree with John Harmston: It looks pretty good compared to a lot of what is out there. And John's an armor guy, as you can tell from his avatar.
But it's not a realistic battle. They're all moving too slowly on the attack, and no one is "going for the kill." But of course, the only way you get that kind of realism is for lots of people to die.
I believe that HEMA is most "real," and reenactment is most useful for HEMA, when we don't let fantasy suspend our awareness of the gap between what we can teach and experience with acceptable safety, and what it's like to fight for your life on a field of blood with a broken pike.
Kron Martial Arts, Orange County, CA
HEMA Alliance Lifetime Member