I have a similar effect on consultant. It’s usually more on the “this isn’t that complicated guys”. I’ll riff off a high level list of things that need to be done, tell them I could do it in a day/week/month and then tell them I want a daily audit of their hours billed and progress made (I’m actually a finance guy but a self taught dev). They usually don’t want the micromanagement so instead they’ll take day to rethink it and come back with a “yes actually i think we were over engineering things a bit” but really we both know they were just planning to pad their hours. It’s a silly dance but usually makes a good working relationship that GSD at an acceptable pace.
I hire consultants from a big corporate and I think they’re used to clients having no idea how to ascertain their projects in terms of reasonable effort to accomplish the set goals.