Well, I personally think that Naruto could pull it off, but the way you wrote it, it almost seems as though you WANT Naruto to win. If Naruto can go 4-tails, then its not really him thats fighting at that point. Its the Kyuubi. If Naruto can prepare Sage Mode, then Orochimaru should be able to prepare sacrifices for Edo-Tensei. I think Fuuton Rasenshuriken would be able to shred Orochimaru the same way it did Human Path. If Naruto needs help to take on the Kages, he could just summon Ma and Pa. I'm sure they'd be of more use than Enma was. and Enma gave a pretty decent fight. Then all he'd have to do is take out Orochimaru, and his influence would probably be erased over them. Tsunade would just need to get hit with the Frog Genjutsu and it'd be over for her. I highly doubt she could regenerate the amount of damage Naruto would put on her without over using her chakra by releasing shousenshou or whatever its called. I highly doubt she could regenerate that damage at all...to be honest.