For God sake the frameworks that are using this, are development frameworks not management! This is why I think managers or unexperienced people outside the team, shouldn't know or care about the velocity of the team, because most of them compare the teams. They, for some reason that I cannot understand, care more about those numbers than the actual deliver to the customer. And by the way...you forgot about something more amusing: you've got a team of 5 with a velocity of 30, one member leaves and the velocity drops to...let's say 17, or another example: you've got a team of 3 with a velocity of 15 and you hire 2 more and the velocity gets to 17, or even worse, drops to 10. In all cases, you'll hear the fire station siren in the office.