[qart]

Again, Manusmriti is not a vedic source. Mentioning it will only serve as a distraction and weaken your argument. The paper by Dipankar Gupta is junk. It does not cite the specific verse numbers of specific vedas. Apparently, Gupta has a lot to say, but gives the impression that he is simply making up stuff as he goes along.

The Wikipedia article is better. But you will notice the article citing the book I mentioned earlier: 'Stephanie Jamison and Joel Brereton state, "there is no evidence in the Rigveda for an elaborate, much-subdivided and overarching caste system", and "the varna system seems to be embryonic in the Rigveda and, both then and later, a social ideal rather than a social reality"'.

If there is really a "large body of evidence", I am still waiting for something concrete that you would cite, so that I can go look it up, in the Vedas.