Read my edited post, i always seem to leave some stuff out after i post my initial post. My point is, he followed Naruto fine in KN0 and was only caught off guard in one scenario(When he blitzed him straight forward). You shouldn't assume he was struggling to keep up with Naruto off of that one time. Especially when Naruto should have been half dead by that point, and magically got stronger and faster in mere seconds. We all know its much different having Intel on someone's abilities than by not having any at all.
He wasn't following Naruto "fine" in KN0. He was managing to keep up, but there are times during that fight when Naruto blitzes behind Neji and it takes Neji by surprise. Not only that, but your claim makes no sense with what I said. My point is that Naruto's speed was able to put Neji in a position where he physically could barely match Naruto. Hence why he wasn't even able to put up rotation at Naruto's blitz.
And it was Naruto's speed Neji was shocked by in that scan, which is why he states Naruto's speed lol.