there should be no doubt.
en.wikipedia.org
The issue I believe with the Americans is they are reliant upon air power and artillery. Not infantry maneuver on the tactical and operational level. They use second generation warfare. If the Chinese model themselves after that, they would be encircled and defeated by more fast moving forces. I did post about Von Manstein victory are Kharkov, where he counter encircled the Russians, a brilliant operational and tactical move. This is something I always find lacking when people look at balance of power between armies. The genius of war is that one man's brilliance can decide the entire thing, which it doesn't matter if the enemy has more troops/better troops/better equipment, if you can out think them you can win.
Binkov's battleground videos are interesting, but in the end false, because its just numbers compared to other numbers, there is no measurement for thought and maneuver, the unexpected. So in my view the Russians would defeat the Americans, China would defeat Russia, and China vs US would be a tactical defeat for China, but strategic victory, like Korea. The Americans have never had great maneuver commanders, who think outside of the box, the just pound the enemy and out produce them. The Chinese just use numbers. All the great American commanders were southerns, like Forrest and Stone Wall Jackson.
So its hard to know who would win, but I know the Americans and Chinese aren't going to think outside of the box, I know the Russians can. The British/French/Germans are better at thinking outside of the box, but they are too small at the moment. Japan is interesting, they will think outside of the box and take risk, but will in the end conform to their systematic nature.