Such a company could be at an advantage in a free market where there were no rules on employment discrimination.
If in your post one would switch the term black woman into white man it would become "If you create a company with only white men.... you could create a very unique culture.". etc
That kind of post would cause a massive uproar for rather obvious reasons.
Yet it's interesting that these kind of posts don't.
We've stopped discussing some key concepts just because it's not allowed anymore. I guess we need the bravery of enlightenment era philosophers once again - to stand up to social pressure in the name of open ideas.
There's only one way to know: get a free market and see whether the companies that hires all Malasians or no Malasians or a mix of Malasians and non-Malasians comes out on top in aggregate.
(Malasians used as an example, not because of anything specific about Malasians. Feel free to replace with Lithuanians if you want. Although the specific cultures involved are probably very important. A culture that has a focus on technology and work ethic would likely beat out a culture that focuses on extended deep sea fishing when it comes to building a startup.)
It's far from being proven yet. Even with anti-trust laws, breaking out companies in smaller entities does not challenge their market position that much, and anti-trust laws have a nasty effect: they encourage companies which are close to monopoly to let a weak competitor survive just to say "hey, at least there is one competitor left so we are not a monopoly". It's just not working well.
I don’t think that means what you think it means