Get your facts straight before posting. He has shown susanoo, and it has been stated that you need amaterasu in order to awaken susanoo. So yes, Hashi has defeated a user of both amaterasu and susanoo, + the 9-tails by his side. Itachi and Sasuke would be no match for him. And you say they lost to Hiruzen? First of all, they were controlled by Orochimaru, meaning they didn't fight at their full potential. And even if they were, Hiruzen is stated to be the strongest hokage, he to would beat the Uchiha bro's. Not to mention that in order to beat them he had to seal them and kill himself in the process. And don't forget that Tobirama knows the edo tensei inside out, edo Itachi would be no obstacle for him. Plus both of the senju bro's have tons of experience in fighting Uchiha, they know about pretty much everything they're gonna throw at them. Kirin cannot be taken into account, since they won't be able to create enough heat for it with Hashi and Tobirama using water jutsus. Uchiha would lose, badly.