How many orals/checkrides have you taken with an examiner where this might be a posed question? I'd say my last P135 ride at work had more questions on the governor operation than your experience
On the 135 side i would agree they will go into detail. But on a multi commercial checkride i doubt it. Nothing wrong in being prepared i just don't find it common for the examiner to make you build the airplane. And the explanations you guys are giving sounds like you are building the governor. I am curious to know the level of detail you were asked about the governor usmc.