Without the Sharingan, Sasuke wouldn't have even been capable of avoiding Gaara's counterattack during the Chuunin exams as he came flying in with the Chidori. Chidori wouldn't be nearly as great a tool for him. His great insight ability to read and predict attacks wouldn't even exist without the Sharingan. There would sure as hell be no Susanoo, no Amaterasu, no genjutsu, no actually seeing the chakra cloud from Deidara's c4, no countering Oro's jutsu to absorb him. No looking into his body to see that those tiny bombs were inside of him. No using the sharingan on the snake boss to actually convince it to do what he got it to do. Hell, he wouldn't even be able to tell where the bombs were hidden underground. See where I'm coming from? Sasuke + no sharingan = death against Deidara. Hence why it's pointless to speculate about Sasuke with no sharingan, just as it's pointless to speculate about Nagato with no Rinnegan.
Do we forget that without the Sharingan, Sasuke wouldn't have even been capable of keeping up with Haku back then? Face it, a great deal of the Uchiha's "genius" is primarily tied to the Sharingan blood limit, and all the advantages it gives them.
As a child, Sasuke struggled, he was nothing in the league of his brother. He struggled over and over just to master that katon jutsu. What do you mean Sasuke as a child was strong and Nagato was weak?
Is a 10 year old who could perform ANY ninjutsu not considered a child to you?
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At 10 he possessed all 6 elemental chakra, and mastered all essential jutsus, and at
ten proficiently used them all. Place young Sasuke up against 10 year old Nagato, if you have the guts to tell me that Sasuke would win, even after what Jiraiya said here, then you are simply being blind to the truth. No child at 10 years old could do the things Nagato could.
You can't doubt the skill and smarts of a person that was able to come up with 'Pain' in the first place. Fight as six shinobi all at the same time, all with a shared vision, shared thoughts, the ability to stop any and all ninjutsu or physical attacks, the ability to summon powerful creatures at will, instant resurrection of bodies to continue the fight.
Animal realm, for existence, can charge towards an enemy while the others look on with their shared vision. Animal realm can bait the enemy into some sort of false sense of security, and right as they think they've got an opening, Animal Realm space-time summons anyone of other 5 pain bodies close range at the last minute to deliver a devastating attack. The coordination and what he wants done to the enemy will be flawless because they never took their eye off the enemy, they all share the same thoughts, and need no words or signals in order to coordinate their actions.
You can't label Nagato as just all about having this powerful doujutsu, and not drop Sasuke into a similar category when Nagato has done far more with regards to skill and genius to make use of what he has. The man created a perfect copy of Itachi and Kisame, maintaining bloodline limits and unique abilities. He created a means by which to monitor any and everything inside an entire country using that amazing rain jutsu of his.
He has the smarts to think ahead when transmitting his chakra signals by constantly changing the frequency so no chakra sensing shinobi can pin-point his location. Naruto's Sage Mode being special, and likely also because of his unbelievable chakra, was probably the only reason why he was able to find Nagato.
I'm impressed with Sasuke, but please don't go overestimating him. What Sasuke failed has, so far, failed to do against his opponents at this kage summit, Pain would have likely already killed.
Is Nagato faster than Sasuke? Sasuke isn't even faster than Sage Jiraiya, and look what happened to Sage Jiraiya!

Despite Sasuke looking as impressive as he does now, with his Sharingan mind you, he has still been having himself a very warm time, and that's putting it lightly, and you actually want to imagine Sasuke without his Sharingan? He would already be dead at this Kage meeting.
Is he as good at taijutsu? Is he as good with weapons?
I don't know, look at what the hell he did to Kakashi, and you tell me.
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Say what you want about it all being the Rinnegan, a funny excuse from someone who usually can't even admit the benefits of the Sharingan to Sasuke, but Nagato created and mastered a wide variety of unbelievable ninjutsu himself. Gedo Mazo, Rinnei Tensei, Chibaku Tensei, and all the rest.
Don't really want to hear about them being the Sage of the Six Path's jutsus because literally every jutsu in existence can be classified as such, and it isn't like just because Nagato had the Rinnegan he had a 1-800 number to the Rikudou Sennin.