I said "if he trained much less", not "if he didn't train at all". For senjutsu and the Kyuubi's chakra he had to train less than others who did it before him, and achieved better results than some of them did. For the other things on my list, he didn't need to train at all.

My list was supposed to show that his skills tend to follow my analysis, not that all them do so perfectly. I still think it's a good generalization.