For those who are experienced with the editor, what is the trick to making a Greek scenario in Poseidon, like the custom scenario "Proteus and Bellerophon"?

If I make a Greek parent city in the the editor, it always plays under Zeus only, so I can't use cattle corrals or enhancements like baths and stone circles.

Not sure if I understand this correctly, but in the upper right corner there is a button "Atlantean", if you click on it, it will change to "Greek".