Tl;dr: Wardley discovered that in business, a visual guide on how to act is a really valuable asset.
Imagine a world in which the hierarchal structure is decided on playing games of chess, except nobody knows a board exists and people only choose pieces to move. The person knowing how those pieces move and are organized can learn how to win. The board is that visual aid, the idea of a Wardley Map is having something equivalent.
Concepts are taken out of Sun Tzu's and John Boyd's work, and merged, the following graphic illustrates this.
You can read the entire chapter here.