Hmmm, EMS Madara easily defeated Muu and Oonoki by toying with them.
Yet he had to use the nine tails to stand on even ground with hashi. If Muu or Oonoki were more powerful, why did he toy and beat them? yet go all out and lose to hashi? Characters are hyped up for a reason. Pain was hyped before his powers were really shown, and look what happened. If hashi was weaker than Muu and Oonoki, why did Madara only have respect for Hashi, he said weak senju were ugly, yet he admired hashi. When madara saw muu, he didnt even acknowledge him. Use logic. You can tell by the way Madara speaks about him that hashi was strong, just by adding some cells of his gives a huge power boost to ppl. You dont see Madara saying, "Oonoki, you are the only one who can stop me." Or "Only Muu can stop me." because if they were truly the most powerful kage, then Madara would have said so, but to him, they both were small.