Power solidifies rapidly. Initially power behave like a gas but rapidly turn into solid matter. We go from an horizontal organization to a vertical in no time.
Dictatorship like North Korea exemplifies this tendency. A father transmits absolute power to his son. The power fails to spill and change can’t take place anymore. To a less extreme extent the same happens everywhere. Leaders often come from the same sociological background either in US or in Europe .
Two ways to concentrate. The Kim Dynasty and a funnel (respectively from wikipedia and wikimedia).
Randomness plus the limited mandate enable to counter-act this tendency. There are no struggle for power using sortition. It will be the dice who decides who will be in charge. The time limitation also plays an important role. Power cannot remain in the same hands. Even if these hands a skilful and well-intentioned at the beginning, they can at any moment becomes evil or clumsy.
Sortition should be imposed at the at the movement inception. Right from the beginning otherwise charismatic leaders impose themselves super fast. These leaders will concentrate power by establishing a set of rules in their favour. This seems the only way to maintain an anarchist organization.
Thank you for reading!