Though it's fun sometimes to compare favorite characters, Plot No Jutsu requires:
The defeat of Madara means the end of the war means the end of the Manga. There's really no one else to fight, and no point in continuing with some random "S-Rank" missions after the world has been saved.
Because this is the final culminating battle of the entire Manga it should be epic; expect a scale no one has seen yet, so comparisons to previous stuff are not really applicable. Additionally, the final battle must reinforce the central theme of the Manga which is teamwork, believing in and looking out for each other. That in combination with the obvious and intentional power up of Edo-Madara makes him more than a match for any one other character.
The destiny the Juubi will probably be the pivotal moment, and it won't be so much about ninja-type fighting. So the final comparison of who could beat who may never occur, but either way it will feel like the fight could go either way otherwise. Madara must be at least strong enough to make it seem like that.
There are a lot of loose ends to tie up, of course, like how is Naruto going to become Hokage, which might be handled during the final battle (Tsunade and/or Kakashi die) or that might be handled in a few Epilogue type episodes. So it may or may not be necessary for Madara to systematically kill off many of the main characters, my guess is no, so he is probably not THAT overwhelmingly strong.
