You raise some interesting points and questions. We just did three Performance Review training workshops for a client last week, so this hot topic is definitely fresh in my mind.
First of all, the "Elephant in the Room" is that almost no one (neither managers nor employees) likes having to go through the performance review process. Therefore, many people approach it with a "let's just get this over with" check-the-box mentality. So step one is to reframe this experience in a more positive and productive way. It should be an open, honest dialogue about the past, present, and future -- focused on the person. That is, a discussion on how things have gone over the past six months (backed up by evidence and examples), how things are going now, and a developmental conversation about the future.
The key thing to remember is that this conversation should be centered on the Person, not on Projects. And it should be developmental and forward-looking in nature. A report card on the past is valuable in terms of lessons learned, but what has been done can't be un-done, so why dwell on it. We use the AID formula when giving this feedback: "Here are the ACTIONS I observed; this is the IMPACT of those actions; and now let's now discuss and explore DESIRED future outcomes." This was a quick and simplified explanation, but it provides a great framework.
One other thing that jumped out at me from your question: If you have superstar performers who are passionate and eager to take on leadership roles and manage their own teams, why aren't they receiving the training and coaching they need to do so? Rather than trying to "support your case," perhaps you should reconsider, and proactively work towards grooming them to take on more challenging, supervisory roles before they get frustrated and bored and jump ship to work for someone else who trusts and believes in them and is more willing to help them to maximize their performance, productivity, and potential.