Columbus has become a scapegoat of history
Thanks for the input, Mary Anne. Yes, there were many things that might be considered "crimes against humanity" committed by the European explorers back then. Columbus had his own faults, too. However, those who single him out for all of the sins of the European explorers are doing an injustice to history in the name of political dogma or political correctness.
And yes, I suspect the Japanese Samurai would've been much tougher opponents than the Central and South American natives. There were a lot of them, they were highly skilled warriors, and they had no fear of death. I doubt the Conquistodors wouldn't had much luck in Japan, other than bad luck.