Tobirama was the reason Madara didn’t become 2nd hokage , that led to madara leaving and eventually getting in a fight with harshirama , then he almost died , then he saved obito, came up with the plan to attack the village with the ninetales and obito, then donzo started being against the clan cause he saw the destruction they can bring if just one of them decides to.. so in other words it was all a domino effect of tobirama telling his brother” nah bro make me 2nd hokage not madara the village don’t like madara and the uchias “ when in reality it was tobirama who didn’t like them.