It works with modern ecorps like this bcs costumers doesn’t have any power to push them.

But in the world of market, i thing there would be a lot more competition and customers will have more opportunities for the punishing a arbiter than does fulfills his promises of costumers.

Did were on Iceland some “Iceland official police”?

No, bcs they don’t needed it, as a article says

“How were people held accountable if they did commit a crime? In much the same way as the current United States civil court system works today. Criminals were forced to pay fines. These fines did not go to the state, but were restitution. If the criminal could not pay the fine imposed on him, then he could go to his godord or a group of family and friends, or some other alliance, and have them pay the fine for him, or if no one would represent him, he could work the fine off via slavery. The poor were at no disadvantage. The poor could sell their right to justice to someone, such as a chieftain or another respected peer, who could collect or make right upon the victim.”