judging from their resume, they fully understood the cruelty of war and the power of enemies. US air domination was clear cut, there was no safe place in korea, if US escalated war, not in china either. mao own safety would be issue.

i think the biggest reason sending mao2 to front was raising spirits. lin biao's hesitation was a big blow, a big dent on morality. that time only russia could rival us, and even stalin didn't want direct confrontation .(people who criticized korean war significance were mainly due to anti-ccp mentality, they didn't want to acknowledge how important it's to china's mainly peaceful life even since, i bet few Americans want another land war with china now).

painting resume could be doen better, mao surely knew. sending son to dongbei in charge of logistics, when war got into wining positons or stalemate, then sneding him to front to "pick peach". we chinese (maybe whole world) have been doing this throughout history.