You are saying something important in a subtle fashion. I’ve heard mechanics say there it’s a difference when the customer brings in a part and says replace it instead of asking to solve the problem.

When asked to solve a slipping clutch the mechanic recommends the best solution that they can warranty. So they recommend replacing the clutch plus any difficult to replace wear items they would touch while in there.

When you bring a part and ask for them to replace it you provide the warranty. So the mechanic replaced the clutch and calls it fine.

I like to be knowledgeable too. But if I find someone I trust to do a job I let them call the shots.

I took the door panel off of my 02 Corolla. Mistakes were made but those panels are pretty forgiving in terms of hiding damage.