That 16 workers running at 16x overseen by 4 line bosses and 1 CEO will suffer more coordination failure that can be avoided by running 256 workers at 1x with one CEO running at 21x, seems plausible and even likely if you assume these are human-like minds.

Robin's scenario is 256 workers and 64 line bosses running at 1x plus one CEO running at 21x who directly oversees the line bosses not the workers (you can check for yourself here). This offers no coordination advantages over having 16 workers, 4 line bosses and one CEO all running at 16x, as far as I can tell.