More mediocre than other people in the company? Presumably the manager is themselves an immigrant, possibly also on a visa. OP's saying they deliberately saddle themselves with people who are worse on every dimension, and thereby make their own job harder. And only managers from 2 countries do this. That should be suspicious to anyone possessed with logic.

> Really, not one other candidate from a slightly different <group> hit your bar?

See now that's a very different question. Are you, like OP, also arguing for diversity considerations in hiring?

> from the same country of origin

But not any random country. Literally the 2 largest countries in the world, which produce massive quantities of software engineers. Preferentially hiring from your "in-group" is never morally or legally right. But why is there automatically a presumption of lower competence when that "in-group" is such an enormous hiring pool?