How many are there and which ones are they? The ones I can think of are Rors and Soods and Mahajans and Rajpurohits and Charans, or at least I’ve never heard of Muslims belonging to these lineages. Even Baniyas in coastal regions had some small-scale conversion to Islam. I’m not as familiar with caste groups of South India and East India.
So Arains probably emerged from around Southwestern Punjab, yet Punjabi Arains tend to be more “east-shifted” than the Ghaggar Arains who live (or until 1947 lived) in Haryana and UP. The consensus seems to be that the Ghaggar Arains despite leaving their homeland ended up being more endogamous than those who remained in the Punjab, retaining their original genetic profile better.
In Eastern Punjab, some Muslim Kamboh/Kamboj “reinvented” themselves as Arains roughly a century ago, though not all did. We know this from the colonial census.
In Western Punjab, Arains were sometimes considered Muslim Sainis, though we know that the two are genetically different (Sainis have higher AASI and I think also higher steppe and less “BMAC-like” affinities). I’ve also seen some people connect Arains to the Rayeens, who as I understand it mostly live around Haryana.
My question is: could the Punjabi Arains have mixed with Sainis specifically to cause them to be more “east-shifted”? Does it make sense genetically? Or were the two just conflated with each other due to similar professions in Western Punjab? Are Rayeens connected to Arains at all or is it just their names sounding similar?