Mmh, even if I kind of agree, the guy is still biaised:
he takes one full paragraph if not more to demonstrate how well european armors could protect against a katana, and then...
"So, even though Japanese armor for the most part was made up of the same quality steel as went into their weapons, European blades would likely not encounter anything especially difficult with it that they didn’t already face. "
hmmf.
Also, he keeps switching weapons for the knight. So, shield? Yeah, a shield is cool, it can bloke super well, much better than you'd think. And then a double handed sword is longer than a katana. I mean, okayyyy...
bleh, I'm editing as I read, sorry

The japanese not being used to fight against shields is bull, helml, he stated it himself, they've fought against chinese and mongols, and they were using shields ( mainly the mongols ).