To get real numbers first we have to parse if he meant meant product manager, program manager, ux manager, and account manager, or just engineering manager.
I assume it's a way of saying engineering is a tiny part of the organization.
Griping about the uselessness of management is precisely the kind of folk wisdom that gets passed around. It's fun to divide the world into do-ers and managers, both because it rights the uncomfortable social hierarchy and encourages action over in-action.