On a tangent, Western censuses like those in America categorize all Asians under an artificial racial category that includes East Asians and South Asians as being Asian Americans. But there is (shocker) no unity among them. A Chindian (Chinese + Indian mix) from Singapore I met saw himself as "mixed-race" and both his Chink and Pajeet sides of the family did not see "racial unity". The Pajeets is seen as brown while the Chinks are yellow/Oriental and would hate for you to say they're brown (like a Pajeet).
In the end, perfect multiculturalism will never work. But I agree with
@Revuelto and their points about making sure the majority ethnic group(s) keep the immigrants in line. I'd say Singapore is somewhat there already. The main ethnic groups are Chinks, Pajeets and Malays, and the Chinks dominate or have more power as they are the majority. And it seems like immigrants from other parts of Asia (i.e - Filipinos, Pakis and other Muzzies/Sandniggers) and the occasional Brit/Aussie/etc who lives there seem to be kept in line.
Even countries like Canada and America aren't as "multicultural" in some aspects. There is a dominant language and people (English and European descendants) and most immigrants become Americanized/Canadianzed to some degree.