i feel inclined to point out anarchy has been realized and many anarchists argue it's an ever-present reality, a state of anarchy exists when there is no authority/coercion. As has been argued millions of times before, most primitive societies did not have a form of institutional authority, for example, native american tribes had chiefs but the postion "chief" was only used for ceremonial reasons, chiefs often didn't have the power to command other people in the tribe what to do or limit their behavior...behavior can certainly be limited in an anarchist group but it's exercised in the form of custom and disapproval of certain behavior rather than law and command