Trigger warning: Angry rant from a guy who has probably internalized some of his provost's own prejudices against non-classical fencing schools.
This is the problem, people will buy this stuff coming from him because he's got a fun costume and flashy moves. But it's just bad, not even particularly knowledgeable. Like he talks about what a "common soldier" fights with, a common soldier would not be fighting with a longsword. That's a weapon for experts, expensive to make and difficult to wield effectively. If someone in your tournament won because of "pure speed and brutality" that just means your tournament is a joke because you're awful and mocking the art. If your only ability is parry-response, you should lose if there's anyone of any skill at that tournament. Don't get me wrong, a good parry riposte is a beautiful thing but if all you have is one tool then anyone who has a tool to deal with that one can beat you. Literally just take their blade and move it, then cut them, if they're not going to threaten you then you can do whatever you want. Yeah it can be fucking scary but a master, provost, or even just someone who's been training for awhile should be able to deal with it and then the response is of course a whole other set of advanced techniques which is why you learn those advanced styles.
It's like, okay, at 2:52 he shows some decent strikes and actually uses the blade properly in a demonstration. But he says you need "sudden burst of acceleration" no, you need small and precise movements. The smallest movement always takes the least time, the fastest (physically) person will never be as fast as the one with the best technique. And then when he talks about spins, yeah, he's right that the Witcher's are bad and you never throw your back at the enemy. But then he demonstrates a spin that is "right" and it's all kinds of wrong. If they kept their point at you, which he talks about briefly, and don't step back which is far from unusual it's called "the guard" you will just throw yourself at their point. Especially if they parry, because you know what plenty of people will do after a parry? Riposte, and if you're still attacking, especially because you don't see their riposte because you've fucking turned your back on them, even if you get your hit in, all you have is two dead idiots once you inevitably land on their point.
"He developed a style of wide sweeping strikes" yeah, that's called a flourish. It might be dangerous to the opponent, but it does not protect you. It's flashy, it's scary, but you're neither using the length of the blade well or its power. Rather than a lot of wide swings from the shoulder which are slow and do expose you, even though the guy scoffs at that idea (it's a serious problem in technique and a totally valid criticism) blows come from leveraging your lead hand and (usually) pushing with the other, often the left. This might not seem like it's strong enough, but it's quick and controlled and that counts a hell of a lot more against any opponent.
These techniques aren't supposed to be for sport, they're supposed to protect you as well as defeat your adversary. Obviously this doesn't matter so much in a modern setting, tournaments are not a matter of life or death though they can get dangerous. But that's not what the art is practiced for, and it's a complete joke to use these kinds of technique in a formal setting.
This guy seems to have learned some of the moves but not internalized the reasons behind the techniques at all. And you can see that in his demonstrations, tense and rigid, because he's trying to do them fast more than he's trying to do them right. And this is the problem with some of the modern teachings and guys who taught themselves by looking at manuscripts or some such. They don't understand it, they mimic.
TL;DR: This guy knows some stuff about longsword and how to do attacks, but he doesn't know why the masters use the techniques they do or the fundamental purpose behind his strikes. Having a cool sword and cloak and belonging to HEMA doesn't make you an expert with the longsword, it makes you a cosplayer. And yes, I'm an arrogant salty know-it-all but god damn it there's an actual art behind this shit.