True, if those groups form, drum roll, a government with exclusive right to use legal force. You know, like the communist vanguard did.
One could argue I supose that the government is modelled on the family. Think is a family has only a limited reach, itself. Under anarchy, the individual would be sovereign but limited reach into the lives of others.
Anarchy, like everything else, is flawed because man is.
Democracy is theory is perfection, no doubt; in reality, not so much.
A monarch has a stake in the game. If he doesn't rule his lands and people well, they lose value and weaken him.