As I read your diary I realized that a very similar phenomenon unfolded here in the United States with regard to "our Indians" (Native Americans). Today most people think of them in terms of tribal units - Navajo, Cherokee, Nez Perce, Seminole, etc. But this was a classification imposed by British and American administrators, not one that could easily be found in pre-contact communities.

Typically Native Americans identified with clan networks, which were bound together by a variety of factors - land rights, language, marriage and ancestry. These networks were very complex, and permeable, especially in the richer and more densely settled parts of North America, such as the Pacific Northwest.

Only during the period of American settlement, when these networks had been devastated by disease, did the notion of a "tribe" emerge. For example, surviving peoples living in what is now eastern Washington were all grouped together as the "Yakama" tribe even though some had no clan relationships, and this was repeated across the country.

What made these tribal identities stick was the law and government practice. Reservations were set for the "Yakama" people, and so on, making what had been an arbitrary definition very real. This was amplified when tribal governments were created. Over the course of 100+ years, these tribal identities became fixed in place, even though they hadn't existed prior to contact with Euro-Americans.

And the world will live as one

I recall a comment that in Hindu society the British fortuitously stumbled onto perhaps the only society that had a more rigidly stratified class system than that of Britain.  The comment was by a sociologist teaching a   History course entitled "The Expansion of Europe" at the University of Arizona in the early '60s.  I was also aware that the so called "Dravidian" people, who had been on the Indian sub-continent prior to the arrival of the "Indo-European" Hindu peoples had a very different culture from that of the Hindu, and that they had been pushed into the margins in the north but were the great majority in the south.

Dravidian languages, such as Telugu in Andhra Pradesh sort of merged with Sanskrit vocabulary.  Buddhist traditions had been spread over all of the sub continent during the time of Ashoka and the Maurya Empire in the period prior to the Current Era, but Buddhist religion does not imply Hindu social custom.  What is known of social customs in Andhra Pradesh, Tamil Nadu, Kerala, etc. prior to the arrival of the Europeans?

As the Dutch said while fighting the Spanish: "It is not necessary to have hope in order to persevere."