Read Otto F. Apel Jr., M.D.'s "MASH An Army Surgeon in Korea." It's a nonfiction memoir of an Ohio doctor who was a real-life M*A*S*H surgeon during the Korean War. The show's 'Five O'clock Charlie' episode was based on a real life incident with a similar-named North Korean aviator.
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Radar: "Holy cowwwww! It's Five O'clock Charlie." Henry: "That idiot?!" Hawkeye: "He couldn't hit the side of a war."

yes, some of the things in various episodes were based on realncidents in those units.
Like, in the episode "Peace On Us" where they have a oarty and everyone dies their hair and clothes red, was something that really happened in a MASH unit in Korea. They made it the 4th plot, though, since it sounds so unbelevable.
There was one incident, though, that was deemed TOO unbelevable. It was about an entire unit that wanted to go home so bad that they stood out in the cold in their underwear.

Although there was an episode in which Klinger stood outside in the cold in his underwear in an attempt to get sent home. So they did not discard that idea altogether, they just modified it.:wave: