>>/72050/
No idea. Genetics?
>>/72051/
Well sumo is very diverse. Besides Jappos there are Mongols from Mongolia, Mongols from Russia, Mongols from China, Mongols from Kazakhstan.
And then occasionally they have others, when I started to watch in 2020 there were a Brazilian, a Georgian, and a Bulgarian. Amateur sumo is fought all over the world.
The larger Ukro, Shishi is in sumo for many years now, he is 29 afterall. Took him a long time until he rose the ranks to the top division. Aonishiki is way younger, 21, but he also in Japan since 2020. He is more talented than Shishi, but smaller, he holds the ozeki title, which is champion, just below the yokozuna (which is essentially a permanent ozeki title).
From the top of my head I can't name other gaijins. There's bound to be some in the lower divisions.