The Hagoromo clan was the clan created by the Sage of Six Paths Hagoromo Otsutsuki. In the beginning, this clan was a symbol of peace and the origins of ninjutsu.
However, something happened and that all somehow changed.What change am I talking about? Well, long after Indra and Ashura the Hagoromo clan to turn bad.
When Indra and Ashura split up, Ashura became the leader of the Hagoromo clan and Indra began his one clan called the Uchiha.
As we could see from Naruto Shippuden, the two clans continued to fight each other but somewhere something happened and the Hagoromo clan lost its peaceful ways.
Buy the period of the warring state’s, the Senju and the Uzumaki clans, who were derived from the Hagoromo clan, were enemies of them.
As reported by Nerds4LifeBlog, in episode 367 of Naruto Shippuden, during a flashback of Madara and Hashirama; it was revealed that the Senju and the Hagoromo clan had become great enemies even despite the fact that the two were once one clan.
During this episode, Hashirama Senju’s father talks of their clans long enemy in the Uchiha and then places the Hagoromo clan in the same category.
The Senju clan were once the clan of love, which is why Ashura chose to reincarnate himself in a Senju called Hashirama and later an Uzumaki (another branch of the Hagorormo clan) in Naruto.
That means Ashura chose an Uzumaki and a Senju over his own original clan, which still existed at the time, at least for Hashirmama anyway.
Sadly there is evidence that the clan was still around during Naruto’s time, but the clan was around during the period of the warring state’s.
We see proof of this when Madara and Hashirama first meet by the river. During that episode, a body floats past them, with that body turning out to be a Hagoromo clan member and an enemy of the two of them.
It hasn’t been revealed when the Senju and the Uzumaki clans separated themselves, however, it was likely done due to the Hagoromo clan changing for the worse.
The Senju clan was now considered the clan of love, which is why Ashura chose a Senju them for his reincarnation over his own clan.
This indicates to me that the clan Ashura inherited from his father was no longer the peaceful clan it once was, otherwise, the Senju most likely wouldn’t have branched off and Ashura might have picked a Hagoromo member for his reincarnation.