I think it has to do with purity of the gene pool. It’s not indiscriminate. They think the more outside blending with the gene pool, the more barbaric the people are.
They would look at Blue eyed blonde haired Swedes being high on the list.
I am a 6 foot 2 inch German/Finnish/Chezk blend from Nebraska.
One of the managers told me “You are why the the Great Wall of China was built”. I said something like “That is why my people took your gunpowder and made cannons. Remember how the US opened up the trade markets of Japan.”
Got a laugh out of that. I also found that some Japanese view China and its civilization as a corrupted version of Japan. Never had time to dig into that, but they would claim some of China’s inventions as their own.
I actually enjoyed negotiations with the home office. My boss would use me to unsettle the home office at times. They knew I was doing as instructed, and would follow the script. It saved them some face and me a lot of time.