Board Thread:Naruto Discussions/@comment-38812954-20190926004630/@comment-33286580-20190926031139

this is speculation on my part...

See, the village was primarily founded by Uchiha and Senju and slowly and steadily other clans joined in.

Konoha was the first of its kind village so there were warring clan era hadnt really ended. So Konoha would be under considerable threat as many clans who probably didnt join Konoha attacked Konoha.

now, since Konoha was formed, i would say it didnt take long for the Shodai to be chosen. by that time Konoha probably didnt even have as many clan as it now as. we can even say it mostly consisted of Uchiha and Senju and some civilians who settled in the new village.

around that time, Madara defected since he apparently had no shot at being the Hokage. it probably wasnt that long since founding of the village. it caused the battle at the VOTE.

it ended in Madara defeat and formation of the Konoha Police Force formed under Uchiha Clan. it ened up keeping the Uchiha inside the borders of the village to maintain peace, while most Senju went out in the battlefield and fought off any enemy clans that threatened the newly formed Konoha. many probably died in those times.

and then soon enough First World war probably happened and again Senju were the primary fighting force, leading to more lives lost.

by the end of it they probably werent many Senju left so that marry their cousins (if you actually see the clan structures you will see that most marry into the clan, at least as far as the big ones are concenred) and so they married outside of the clans.

even small in numbers now, they would still be fighting at the frontlines as the founding members of Konoha and so the following wars and conflicts probably reduced their numbers furhter to non existence.

the Uchiha meanwhile survived because most members probably stayed and joined the Konoha Police Force and were mostly worked inside Konoha