There's nothing implying Naruto was moving particularly fast against Muu, given that his Shunshin > his chakra arm in speed and his chakra arm already blitzed Muu. We don't even know where he was coming from, if he was coming from far away Muu would have the ability to perceive and react in time.
Muu didn't dodge KCM Naruto's chakra arm strike though, he completely failed to do so actually even though the attack came from a distance away. Gaara did literally squat other than stop Naruto from falling.
So you admit Naruto landed FRS on Ay3 successfully without him being able to evade it? It was merely a matter of range, and if Naruto can blitz a Raikage in close range, Jiraiya won't really have a good time.
Mu didn't anticipate the chakra arm at all, he was charging up Jinton. This was made very clear actually. Check the scan. Just make sure you don't omit details like needing help in the first place
Yes Naruto was able to land on the 3rd attempt. And it wasn't a blitz, that term is so loosely used I don't even pay attention to it anymore. He was right behind A3 when he caught FRS and slammed it into him. I don't think we ever seen a clone of his use Shunshin.
Jiraiya won't be fighting clone Naruto up close, A3's only trick is to be quick, durable and run at you. Far cry from how Jiraiya fights.