Guys... Madara will not "break up" with Hashirama
They will found the village TOGETHER
Remember when Onoki fought Madara when he was young? He asked why he was attacking him if they had a truce, and Madara said that Hashirama's truce was bullshit... that clearly shows at that time they were still in the village together, but they started to diverge in how to conduct the village...
IMO Hashirama will figure out with Madara how to stop the war between Senju x Uchiha, which will lead to the creation of the village and make them the leaders of each clan - but Hashi will be the first hokage in the end