So far I've watched the first one.
Basically it looks really good to me, but here's where I see it diverging from HEMA (in terms of formal technique):
1. They tend to use the buckler as a small shield, rather than protecting their sword-arm with it. The manuscripts are pretty clear about doing the parries with the sword, not the buckler, because it's too easy for the sword to skip off the buckler and hit anyway. I'm guilty of this too, to be fair.
2. Almost no bind-work (winding and thrusting from the bind). This tends to go out the window anyway, in the heat of a fight, unless you're particularly skilled at it. But for those who can get good at it, you can very quickly regain control of the center-line and land a blow before the other guy's much larger motion can come around again.
3. Very few thrusts in general, if any, and instead they're favoring very large sweeping blows. These are OK, of course, unless you leave yourself open. Tactically speaking, often a smaller, quicker motion is better, but not always. And it depends on the techniques in question. For instance, the Bolognese sword and buckler system relies on large swings more than the German or I.33 systems do, partially due to the type of swords they used.
But having said that, they all fight well and it looks pretty good to me. I'd say it's more reminiscent of the Bolognese sword+buckler than anything else.
