Hi Andrew,
I'm sure you know, you get what you ask for (or measure). Organizations assessing individual's velocity will get 'individuals' and will also get 'individual velocity' that they are looking for. However, if they want to tap in to the collective wisdom of the team, to deliver impact and meaningful value for their customers, that's what they would need to ask for.
Douglas McGregor's theory of human motivation, theory X and Y calls out, rarely a manager believing in theory X has Y type people reporting to her and vice-versa. Positive Psychologist and Harvard Professor Shawn Achor explains that a manager's belief and bias about a team member manifests in the way of behavior, opportunities provided and also the way the manager assesses his team member. So be careful in how you categorize people.
I would like to quote what my friend - Madhur Kathuria (CSC, CST) says - "Build a superstar team instead of team with superstars." An effective ScrumMaster can play a vital role in building that team synergy.
Thanks,
Kamlesh Ravlani