[dragonwriter]

> the 6 layers isn't really true, in part due to line managers can manage 15-30 people

Yes it is, IMO; any layer above line managers over nonprofessional staff should have a span of control not greater than about 3-5 subordinate managers with full-depth (1 level less than the manager) organizations and a similar number of supporting staff that either have no reports of their own or supervise organizations about 2-3 levels less deep than the manager above them. Yes, lots of real organizations have broader spans of control, but lots of real organizations also are what the author describes as “immoral mazes”.