re: The joy of sects
E.R., your analysis and perspective seem to be limited to city states of classical Greece and Rome.
You may want to look at the religious aspects of Mayan city state wrafare, and the religious aspects of warfare in the first irrigation agriculture socieities of the ancient near east.
If you really want to get some skill, you might examine the role of impact events in the formation and development of religions.
I find examining the spiritual aspects of bad planetary science to be fascinating.