Not if you look at Naruto's track record. He has defeated enemy after enemy that on paper is stronger than he is. He is known for never giving up and that is what makes him come out as the winner every single time. If you never accept defeat and keep fighting then you haven't lost. And even though Madara is in his own rank, Naruto don't care and Naruto knows that the only way to end the war is the kill Madara and Kabuto, but if he doesn't do it his own way, then it's simply no reason to do it. That is just how Naruto is.