As I said with Hokuto Shinken; Jagi trained his arse off every day and was a much better martial artist than I could ever hope to be. Guy punched down a tree to prove that he was even worthy of training. In like... ten years of training, alongside Kenshiro, Raoh and Toki, he still was hideously weak compared to them because they were all prodigies. I am worse than Jagi so I would worse at HSK than him.
I know little of Saint Seiya, but Seiya is meant to be pretty amazing at his martial art and was trained since he was... what... ten to do it?