So, did the people of each temple have alliances with each other?
Were they forbidden from fighting amongst themselves?
The simple answer was no.
They were allowed to fight whoever they wanted as long as the other individual was also a member of a temple. The three temples only served to separate people so they could be more easily managed.
The heads of the temples were required to maintain good relationships with each other. The current heads were actually close friends. Under their command, chaos couldn't come to this island. Prosperity thrived because of the temples' existence.
Civilization thrived in prosperity.
This landscape was not filled with castles made by people who only wanted to move on to the next island. It didn't just have two cities to contain the people who weren't allowed to build as they pleased.
The third island had the largest population of the five by a large margin.