I think Chinese are one of the most insular groups overseas. When you see Chinese people they tend to be in groups, with other Chinese people.I don't know, maybe the Pakistanis I know are just insular.
When I go to Canada to visit my relatives, we speak to each other in Cantonese (or Mandarin), we go to Chinese restaurants pretty much every day, we meet family friends... who are of course all Chinese.
When I go to Malaysia to visit my relatives, exactly the same story. We meet other Chinese people, talk in Chinese, eat Chinese food, etc.
As for marriage, Chinese men tend to prefer women of East Asian appearance, hence all the imported wives from other East Asian countries. East Asian women on the other hand are a lot more open (or "tolerant" perhaps). And it helps that other ethnic groups tend to see East Asian women as desirable, even the very mediocre ones.