Well, another great subject! We have had several HMO's, "PPO's", Insurance Companies or whaterer over the years, and I agree that most have their focus on the bottom line ($$, not your health). They try to weeeeeeeeaaaaar you down, to see if you're persistent enough to push them into paying your legitimate claims. If you roll-over, then they win.
I am also very conscious of the pickle this puts our Doctors in, where they need to see too many patients/day in order to make their fees add up to a reasonable income.
One thing that has worked for us in the past is to speak with "higher-ups" as soon as you feel the untrained are not taking care of your business.
One other tactic is to remind those "higher-ups" that they are "practicing medicine without a license" when they tell you the Doctor is doing something unnecessary.... and they are not paying for it. There is always a short silence on the line after you say that.... and many times the argument stops there.
We also learned very early on that we cannot be afraid to be considered "trouble" patients when dealing with Health Care business of any kind. There's another word for what my wife was called when standing up for what's right: *****. If that's what it takes to get what is rightfully yours, then "...sticks and stones..." etc.
Yes, many times it's an adversarial relationship, and most of the rules and grudgingly paid-for services came from the need for lawyers to get into the act, like "Caution: Coffee in this cup may be hot!".