If a hierarchy settles into a strong tree structure, it approaches O(n) connections people have to handle - one bidirectional connection between each person and their immediate superior.
To put it a different way, a hierarchy has potential to scale without limit, or to put it differently again, the larger a system of people, the more they will be forced by necessity into a strict tree structure for the majority of 1:1 communications.
It's potentially a bit better than O(n log n).
If a hierarchy settles into a strong tree structure, it approaches O(n) connections people have to handle - one bidirectional connection between each person and their immediate superior.
To put it a different way, a hierarchy has potential to scale without limit, or to put it differently again, the larger a system of people, the more they will be forced by necessity into a strict tree structure for the majority of 1:1 communications.