> Even if the top performers are insulated from the "heat" there are a non-zero number of them that this won't sit right with and/or they are affected and they leave.

Or some of the low (but not negative) productivity teammates get pushed out and the top performer follows them because keeping them around was good for morale for reasons unrelated to their actual job descriptions (or their individual metrics were rubbish but they also were valued assistants who unlocked the top guy to work at full speed).