I don't get this thread. Sasuke showed tremendous improvement but Naruto didn't? Are we going to ignore the fact he was running and could activate Sage Mode, something that was dubbed impossible? Are we going to forget that his speed increased to the point where he could save Chou-Chou from Shin in the blink of an eye while moving Sarada too? Seems like improvements to me.
Furthermore, people need to learn to spot things that don't make sense. Naruto was called rusty and that was why his "performance" was lacking. What? That doesn't even make sense. The term "rusty" isn't something that was emphasized in Naruto. Hizuren spent 12 years behind the desk and he wasn't "rusty". He was simply old and lost most of his power. Even Danzo wasn't "rusty". Did Onnoki seem "rusty" to you? What about Ay? Even Tsunade? Yet Naruto, who spent even less time with the title "Kage" became "rusty"? Oh please

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That was simply plot induced stupidity, better known as PIS. It was simply a convenient way to extend this manga series by Kishimoto. It's the same reason why Sasuke didn't use Amenotejikara and save Sakura.
But getting on to the point of this thread, I don't see Naruto being weaker than Sasuke and while I think Naruto is stronger than him (due to him being a Jinchuriki) it wouldn't be that easy.