Board Thread:Theories and Speculation/@comment-26904721-20150820181613/@comment-734582-20150823114308

Idrinktearsforsupper wrote: Now this became really stupid really fast. Agreed.

BakumatsuWarrior wrote: So the idea that the Senju were wiped out due to warfare seems rather unlikely. I didn't say they were wiped out due to warfare. I said that in reality, things are usually a combination of factors. A combination of being exposed to above-average amounts of warfare, a completely different attitude to the village and natural intermingling with other clans are what i consider the top 3 reasons. Note that the Hyuuga kept their clan healthy via the whole Branch/Main family system. Both Hyuga and Uchiha put significant pride into being a member of the clan, whereas Hashirama's idea was that the Village should be put above clan.

GoldLiger wrote: The reason MN is a Senju Is that one guy deviates from everyone else, and so is assumed to be the status quo rather than what he really is, namely an exception to the rule.

We know nothing about Ashura. Maybe he simply was Kurama's jinchuriki. It's far more logical than assuming Minato, who has no senju connection, is a secret senju.