Concrete, wood, steel, stone, and brick are basic materials that can be arranged infinitely to create a structure. It could be some form of a building or perhaps a wall. These materials can be used alone or in combination with each other to create or define space.
It takes time to learn to learn the particular properties of, say, concrete or wood, and the ways to use them most effectively. For instance, you would not use stone or wood to build a skyscraper and it may be too labor intensive to use concrete to build a small house. It is critical for an architect to become familiar with the specific material characteristics of each so that he or she will be aware of it's limitations and potential.
To a leader, people are the materials that are being employed to build an organization. In a way, they are the foundation upon which your business is built.
Do you have the confidence to say that you know the capabilities, limitations, and potential of your team? Develop your team, and they will develop you.