Please guys, stop using the Sannin battle to prove anything. Everyone there was handicapped and summons pretty much did most of the fighting anyway.
Also, too much credit is given to Susano'o and that Yata Mirror of his. It was never tested against very powerful attacks. Seriously, Susan'o was proven to be a great defense, but I always wondered, for example, what would happen if it got hit with something like mountain hollowing super great ball rasengan. I seriously doubt even Yata Mirror could just repel it that easily.