Muichiro Tokito was a Hashira at just 13 and killed an Upper Moon at 14 with no sweat, he even gained a demon slayer mark. He really is a true prodigy. So why would he need anyone to train him?

Even if Muichiro's training was right now on break you were still training. You haven't gained the type of treatment Tanjiro would get from Muichiro so as usual Muichiro was straightforward. It's crazy that he's actually toned down his attitude

"Train me."