Part of the difference between decentralization and citadelization lies in the layering of collective self-interest.  To be completely self-sufficient is nearly impossible and an unwise use of time and resources when compared with the camaraderie and security of gathering into a small tribe.  The Phalanx of ancient warfare was so successful because of its network effect of group attack and defensive shielding.  There is an ideal size for any organization based upon its purpose and it is only rarely a solo operation.

As part of my spiritual journey, I studied the Gurdjieff Work for a number of years.  The introductory concept taught to everyone was that of self-remembering to separate from being overly identified or possessed by a thought or feeling. Later in the Work this was defined as the first conscious shock or conscious breath.  Every tradition has its own name for gathering the attention, moving it to a point inside the body but away from the brain and sense organs, and using various techniques to get some level of conscious control over it.  To become clear enough to listen to our inner voice of conscience, we need tools to separate ourselves from the crowd of humanity.