I didn't mean it so much that way. I meant that it would be unlikely that Pain would be the leader if he was weaker than they were. It would be hard to have any sort of authority if he could just be taken down so easily. I guess being the strongest isn't necessarily a prerequisite to being the leader of this group, but I think it's implied in the Manga. He calls himself a god and everything, I don't think he's too scared of anyone in his organization.