Board Thread:Theories and Speculation/@comment-32369776-20170708034118/@comment-734582-20170716081524

Actionmanrandell wrote: since there has been no mention of asura's children forming both the senju and uzumaki clan, the only logical assumption is that the uzumaki clan is a branch off of the senju clan. There's also no mention of Hamura's clan splitting in two, yet we clearly have his descendants on the moon and the shinobi world.

So no, i don't find it a logical assumption at all. Kinkaku and Ginkaku were said to be related to the Sage, yet they're not know to be Senju or Senju-descendant. I find it far more likely that the core support/family of Ashura founded the Senju and the periphery founded other, related clans. It seems that only the Uzumaki retained any strong political and economic connection though, hence that relationship was mentioned explicitly.