An argument against hiring from culturally heterogeneous nations is that it doesn’t consider the friction caused by cultural and language differences. The most straightforward refutation is if people of different nationalities worked poorly together, employers would account for this when hiring. In reality, we see companies in the UK often choosing to hire immigrants.
Overlooked by the immigrant worker nay-sayers is that all people are different, even those born in the same hospital and raised within miles of each other. In a world where people worked together problem-free, managers’ jobs would be far easier or completely redundant. Managers get paid to unite teams despite their differences, regardless of their origin.