Much of Sun Tzu's writing describes the relationships of his elements. This is why it is so useful to think about positions when interpretting his writing. The elements of the system are not defined primarily by their essences. His elements are defined by their relationship with other elements.
In the West, our history is defining things by their essences, that is, what they are. Our chart of elements describe the inherent characteristics of things. One type of molecule has a different nature than another. An electron is different than a proton. And both are different from a quark. A thing can be attributes in itself. Iron is hard. Tin is soft.
Sun Tzu's view of the elements was different. Sun Tzu defined elements by their relationships, what they do, and how they interacted with other elements in the environment. A position is strong or weak, not in itself, but depending on its comparison with similar positions. Iron is soft when compared to a diamond. Tin is hard when compared to water.
This concept is very much like modern physics. Everything is made up of particles (of vibrating strings if we get into string theory). Those particles have different characteristics because of the way they interact with other particles. Protons have mass because of the way they interact with Higgs bosons. Electrons hav less mass because they interact differently with Higgs bosons.
Diagramming is useful
Much of Sun Tzu's work explain these relationships but his explanations are lost if we don't have the right mental picture. This is why diagrams are useful. It his era, basic elemental diagrams were in everyone's head. Part of the common knowledge.
Think of his elemental diagrams as his equivelent of the periodic table of elements in his era.They shows the relationships of elements in modern science. Sun Tzu developed his unique system, basing it on the system used by classical science. This system is largely based on conceptual connections. Man of these relationship read like metaphors but they actually go much deeper. The ancient Chinese scientists and philosophers relied upon the many connections in this system to express complicated ideas without having to explain them in detail.
Sun Tzu's system is less about specific concepts themselves than it is about their relationships with each other. It is less about individual actions than it is about the larger processes in which those actions play a small role. Everything is connected to everything else and systems must be viewed as whole not separate piecves. The Art of War itself doesn't describe these processes in detail, referring just to Sun Tzu's differences with the classical models.
Ancient Chinese science had a system of diagramming that captures relationships and processes. People today may be familiar with Chinese nature diagrams from feng-shui. The Art of War doesn't describe this model itself. The model comes only from studying Chinese culture and history.
Almost all those who have translated Sun Tzu's The Art of War are unaware that this system even exists. The connection between this ancient system and Sun Tzu wasn't made until Gary Gagliardi began diagramming Sun Tzu's system as part of his lectures and writing. It was an audience member who pointed out the connection between his diagrams of Sun Tzu and the ancient Bagua of Chinese science.
It takes an entire book to describe all the relationships in this diagram and their relationships to Sun Tzu's system. Gagliardi created such a work; he replaced the classical elements in traditional diagrams with the elements that Sun Tzu describes, creating the key to transforming a collection of vague aphorisms into a rigorous system. He explained this diagramming first in his award-winning Amazing Secrets book and later in his training seminars.