The "performing" part isn't about the individuals on the team, but the team as a whole. Every staff changes (adding or removing) slows down the entire team for

The "performing" part isn't about the individuals on the team, but the team as a whole. Every staff changes (adding or removing) slows down the entire team for a period of time. This isn't also about people not moving and denying them career or personal opportunities, just a consequence of team changes. It's a reaction to the idea that once you add more people to a team or an organization, you will see productivity gains almost immediately. It tells you that actually they will take some time, and often, a LOT more time than you initially thought.