> Not sure why two immigrants from Austria and Germany are 'diverse' but two immigrants from India's Nagaland and Gujarat, who have different religions, cultures, languages (even facial features, if those count) are clubbed together.

That's an interesting point. When asked by others where I am from I normally respond with "I am from India" - but it would be more appropriate to say "I am from Tamil Nadu" (an Indian State north of Sri Lanka).