Government
Athens tried democracy, Sparta was ruled by a small group, and a lot, like Argos, were ruled by one king. As you can see, every city-state in ancient Greece have their own structure of government. The government that Argos chose was Monarchy. Monarchy is ruled by one person (usually a king). They are mainly "dynatic", meaning power is passed from generations. That's why the ruler or king is almost never chosen by the people.