He was planning on being Hokage by brute force so it really wouldn't matter to him if he didn't have the approval of his friends or the villagers. The guy was planning on killing all five of the current Kages and being the sole ruler of the world.
That was not his plan he thought the 5 nations needed to be United by a common enemy like what happened with Madra with that enemy gone he thought the world would go back to its usual state of war so he was willing to be that common enemy
This is not true. He specifically says he will unite them under his rule, before explaining that he will judge the world and deliver punishment moving forward. He didn’t want to perpetually fight with them either, since he assures Naruto he would be the last person he ever killed