Your idea is unfair and would be illegal to carry out. Because it's racist, obviously.
Furthermore, I live in the Balkans area (Croatia) and it so happens that companies from this area do employ people of varied ethnicity, and those do work on the same teams.
Exactly, the only way to get people to accept everyone as they are is to see that they're exactly the same as them. If a person can't put this sort of thing aside and work with a basic dose of professionalism then they should frankly be fired. You can't tolerate intolerance.
You'd think that a nation as varied as the US would know that.
Furthermore, I live in the Balkans area (Croatia) and it so happens that companies from this area do employ people of varied ethnicity, and those do work on the same teams.