Enjoying this discussion. To me the rank of a Mechwarrior and their standing as a mechwarrior st two different things. One of them is their position in the military hierarchy, and the other is their ability. The parallel with airplane pilots makes this clear. Pilots come with a variety of different ranks, but to many people the fact that someone is a fighter pilot (assigned that role and actually competent at it) is far more important than their exact rank.
I see it the same with mech warriors. Unless they are personally notorious in some way, or well known as a mech commander, their status as a mechwarrior is going to be more important to a LOT of people than their exact military rank. This is even going to apply to a lot of people IN the armed forces, particularly those who are of much lower or much higher ranks. The general responsible of a regiment or an invasion doesn’t care overly much about the exact position of their mechwarriors in the org chart all the time - they just want to know if they are available for service and how good they are. Likewise the repair and support staff don’t particularly care what the rank of the mechwarrior assigned to the war hammer is - their job is to make sure it’s ready for action. The crew chief for the techs in charge of a lance support team may technically outrank a mechwarrior in that lance , but operationally the mechwarrior is going to get a lot of unofficial say so, because otherwise the unit isn’t going to function very well.