There are the rich, then there are the elite rich. There won't be much difference in the eyes of the poor and middle-class people but there would be when you call yourself a rich person.
The rich are someone with money to spend lavishly but the elite are people who can do anything without moving. They not only have money but also power and influence in a country or countries.
The guild master of the Overlord Guild belongs to the elite rich. Though he has no power on Earth for now, because of the game, he established his authority over people who entered Aredia.
With the resources provided by his father, Obadiah Ferlon, James was able to establish a guild and named it, the Overlord Guild. His aim was to become the lord of all people and that is why he chose such a name for his guild.
After establishing the guild he became much more famous than he was on Earth. This was because he earned a rare profession called "Hero".