...as the series went on

https://www.metv.com/stories/harry-morgan-acknowledged-that-it-became-harder-to-create-original-m-a-s-h-plots-as-the-series-went-on

Morgan was frank in his retrospection of the series.

And Linville was sherman

Harry Morgan was right.
That ep., Snap Judgement, the TWO-PARTER about Klinger being accused of stealing a Polaroid camera, shouldn't have been made in 2 eps. let alone 1.
It was very formulaic writing.