Supermarket staff being segregated by ethnic group?

Disclaimer - I am a British born Asian and live in London.

In my area I am surrounded by several chain shops all within a few metres of one another - Tesco, Sainsbury's, Co-Op, Iceland, Boots, etc. The area I live in is primarily White and Black African/Carribean, very very very minority Asian.

Except each of those supermarkets are dominated by different South Asian ethnic groups. The Sainsbury's by Indian Gujarati speakers, the Boots by Pakistani Urdu speakers, the Co-Op by South Indian Tamil speakers, etc. But the Iceland is mixed and VERY reflective of the local demographic.

So my question is - considering the very difficult job market - how do people feel about this? Are the stringent tests put in place to enhance diversity and equality in the workforce is somehow being circumvented during the hiring process to the point that people speaking the same non-English language end up in certain stores? Do the chains care about the fact their recruitment processes put in place with much consideration seem to be leading to biases? Am I seeing things?

Would love to know what other people have seen and whether this is a real problem in the current job market that you've come across too?