Hey that WAS me.
I was a perfectionist about this too, but have started being more honest about it. No matter how solid your prep is, people are going to “kill the mayor” (a phrase harkening back to a game where the PC’s idea of saving a town from invaders led by the mayor’s brother was solved by killing the mayor so there’s no more grudge).
In a recent game, what I prepped for a society of ice elemental humanoid villains ended up being used for a friendly clan of frozen waste hunters.
Perfect prep doesn’t exist because it will always be PLAYED. Players ruin everything 😉
What was the question again?