Wow that's crazy!!
I'm certainly no historian but I know there are a lot of inaccuracies in commonly held fantasy beliefs. That said, that video kind of blew my mind! It's like Judo in armor. I was also shocked to see that they didn't swing their swords at all and instead used them like spears.
So obviously D&D combat mechanics aren't a realistic representation of actual medieval combat. So my question is, are (or were) there any RPG systems that are more simulationist? Not sure I want to play a system like that per se but it's definitely sparked my curiosity.