First of all, I explained to you in my comment why Madara CAN be used, so please, read before you copy/paste. Secondly, you may be using Itachi in your argument, but he still counts unless you're pitting Kabuto vs Itachi, which in this case (Kabuto vs Nagato), you're not.
And basically your only argument for Kabuto was 1. CT and 2. the dog summon.
Firstly, you seem to forget Kabuto's genius. He is certainly smart enough to figure out the counter to CT. And all that is necessary is 1 Jinton by Muu to destroy the core and the jutsu is ended.
And you seem to forget that Kabuto has summons of his own. THEY can take care of the dogs. And his edos aren't going to JUST attack the dogs like you seem to think. They will be going for Nagato. And the number of them would make that 5 second interval seem like an eternity. And the fact that he really can't be killed, and his edos can't be killed...he could certainly outlast Nagato, even with Nagato's massive stamina. Nagato has no answers.
Also, since it seems that you DID read my comment about Madara, let me explain. Yes, Madara was never under Kabuto's control. Why? Because if Kabuto took complete control of Madara, Madara would have been weaker. Kabuto wouldn't be able to fight nearly as well for Madara than Madara could fight for himself. But the fact of the matter was that if he wanted too, Kabuto could have certainly taken full control of Madara, since he was one of his edos.
Naruto would also lose to Kabuto, don't know what your thinking. Nagato is a part of Kabuto's arsenal in this scenario as well. And Naruto cannot beat all of Kabuto's edos at once. It's not possible. I don't even want to explain. Naruto wins.
And I will admit, I was wrong about Deidara beating the Raikages, I forgot about his weakness against Raiton users. But the reason why Sasori and Orochimaru beat them is poison. The Raikages have weak points, and those points are their eyes, mouth, and nose. Some poisoned iron sand getting there from the third kazekage puppet would spell Sasori's victory. And considering the sheer power of the iron sand, he may even be able to pierce their skin (particularly A's). Sasori can also produce a MASSIVE cloud of poison gas at whim. With that he could also easily win. Orochimaru's true form's blood also spews poison gas, and since neither he nor Sasori can really be killed, they will eventually succeed in their poisoning attempts. And about Sasuke, he just has to wait for the Raikages to come to him. If he can get close, Amaterasu would be easier. But I will agree, I was definitely underrating the Raikages a bit, that one is hard to judge.
I don't know about Deidara beating Gaara, but Sasori does. Sasori's iron sand is powerful enough to pierce Gaara's sand for sure. And at the very least Sasori can outlast Gaara. Also, about Sasuke, Gaara cannot block Amaterasu. He blocked Sasuke's attempt at manipulating already existing flames. Amaterasu himself he cannot block. And either way, there are still already too many people who can defeat Gaara for him to be in your top ten.