Originally Posted by Lunatock

Lots more to consider than just the Katana and the European Bastard Sword. Knight Swords and Knight Armor for example. They depended on brute strength since the swords and armor were so heavy. And when knights fought the objective was to knock your opponent flat on his back.

And the different types of weapons & tactics. Let's say castle or house warfare. Unlike Knights, samurai would use bows & arrows at medium to close range.
And you ever been inside any Japanese buildings? Not quite as spacious as buildings in other countries. Which would suck for fully suited knights and most of thier weapons. Samurai could just unsheath some Wakazashi's, which were made for indoor fighting. And odds are the knights would have to use daggers, as most of thier other weapons would be too big & clumsy, considering the limited space they'd have in a Japanese fortress.