OKai I know this sounds dumb but sasuke is the top ninja. Yes naruto is the main character but
sharingan beats everything
. First of all Madara is strong but sasuke is stronger. Tobi been watching him improve his sharingan for the past time. He has the power of Madara uchiha but he doesn't even realize it yet. Right now who knows what sasuke is up to . It's no that he's weak but he too slow in improving his sharingan, but when he had new eyes it was a boost and tobi supported him. The only reason why tobi lied about him being Madara Uchiha was that he feared sasuke. Danzo is almost like Tobi. Right I sasuke can defeat Danzo he can sure defeat Tobi even if tobi posseses the rannegan. When sasuke learns to control his eyes then you'll understand i mean he is OP