So the Senju and Uchiha existed before the sage did?The clans could have existed prior to him existing, ever thought about a boy and girl falling in love with each other and making a baby? Do they have to be from the SAME clan? No. He could of just passed on the different parts he inherited into his two sons ( who just so happens to get equally half of his power )
-Rep because you can't just leave it as it is?Geez, you're an idiot.
Good bye