Sub-caste fusion is less practicable than cross-caste fusion.

Evidence

There is a view that in the reform of caste, the first step to take is to abolish sub-castes. This view is based upon the supposition that there is a greater similarity in manners and status between sub-castes than there is between castes. I think this is an erroneous supposition. The Brahmins of northern and central India are socially of lower grade, as compared with the Brahmins of the Deccan and southern India. The former are only cooks and water-carriers, while the latter occupy a high social position. On the other hand, in northern India, the Vaishyas and Kayasthas are intellectually and socially on a par with the Brahmins of the Deccan and southern India. — Ambedkar, B R, Annihilation of Caste_ The Annotated…, 944

Categorization

• QUESTION: Evidence that ranking within a caste varies regionally — worth chasing how Brahmin social standing maps regionally.
• XREF: Connects to the reader’s broader caste-annihilation reading: sub-caste abolition as a proposed reform path being rejected.