Size matters. Plain and simple.
The description of this match reminds me of Dan Severn vs. Royce Gracie.
Interesting to note difference in this description vs traveling/catch wrestling that did not typically have problems with the jujitsu types.
Also notice the total racial stereotype of assuming Japanese men are tinier and weaker than white men.
I don't think the Pacific theater Marines would agree that the Japanese couldn't hold their own in hand to hand...equally trained...
Teddy was a little off now and then.
Japanese, who though very good men for their inches and pounds are altogether too small to hold their own against big, powerful, quick men who are as well trained.
The equally trained part is the point if a smaller man beats a stronger man then generally they are better trained or at least more skilled.
You didn't get it I guess, so you made a straw man, complete with a irrelevant Wiki reference to try somehow convince me Teddy, one of the most overtly racist US presidents in history, wasn't being overtly racist in his comments about the Japanese.
Teddy was not talking about averages and statistics and no, Teddy did not say "average Japanese", especially since the statistics you referenced were not even available in his time (unless he had a time machine and internet access).
Teddy literally said:
one of our big wrestlers or boxers, simply because of his greatly superior strength, would be able to kill any of those Japanese
I think there was a much more casual attitude about saying racist stuff back then and it was perfectly respectable to have racial theories (and think some races were superior). So...I think he was just saying the skill was not enough to overcome a bigger wrestler or boxer like you find in the US.