That's not how they write the history of their Korean tactics, whatever it's worth. They see themselves as successful in deploying huge numbers of light infantry that overwhelmed American forces by their decenhttp://bevinalexander.com/excerpts/korean-war/tactics-chinese-communists-korean-war.htmtralized control.
Mao wanted to surpass the Soviets, and cooked up the volunteer invasion scheme; the Russian advisors unexpectedly supported the idea. Oddly enough, the North Koreans had some top generals who opposed the idea, on the basis that the US had very deep experience with large amphibious invasions (from WWII) and a peninsula was an ideal geography for a decisive result from such an invasion. They were overruled, and during that terrible UN retreat to the Pusan perimeter, they looked dead wrong. It didn’t last. Attempts to crush the perimeter failed time after time, and a breakout started as a diversion just ahead of the Inchon landings.