Against the Chinese and the Koreans, agree wholeheartedly as they were new to using this sort of sophisticated weaponry and what may have made good foot soldiers does not work in the air. (There is the story told by the Russians of one Chinese colonel ordering his squadron to do as he did, and then once he was shot down the other seven just froze, waiting to get picked off.)
The early Russian pilots were at least as good in the air as the US, but suffered from one basic technical innovation we had and they didn't: the G-suit. The reason they now give as to why they wanted to get their hands on a Sabre was its G-suit controller, as they wanted to reverse engineer it so their pilots could get the max from their fighters. As noted before, many of their pilots went home in self-imagined disgrace after 100-120 missions due to internal organ damage caused by fighting in high G conditions without one.
Later pilots tended to be newbies as we noted the other day in the discussions on the 190th IAD.