I've worked at many different companies. The first were all waterfall (because XP hadn't been invented yet). My next scrum team sizes were 5 (scrum), 3 (no scrum), 2 (no scrum), 15 (waterfall), 4 (scrum), 4-10 over time (scrum), 5 (scrum), 6 (scrum), 9 (scrum).

I've never seen what you describe actually happen (although I know that this is the theory behind it).

TBH I haven't really noticed much difference in the accomplishments of scrum and non-scrum teams.