From PhilPapers forum Philosophy of Religion:

2009-10-30
A theory of religion
Reply to Jim Stone
OK, back from conference. I don't have much more to say myself not being conversant with the empirical literature on comparative religion. But I'm interested in the response to the Chinese religion (or "religion"?) counterexample because it poses the question of individuating religions that I raised.

About the worship of stocks and stones, just from my admittedly recreational reading, the conventional story is that the indigenous cults of the chthonic deities merged uneasily with cults of the sky gods imported by northern invaders. By the Classical period you have the official religion of the city gods, the ones on the Parthenon frieze, alongside the folk religion of the masses centered around the godlets of boundary markers and crossroads, household gods, daemons and ghosts, etc. just barely polished up and recruited into the pantheon. With the collapse of the city states as significant political entities during the Hellenistic period, the official religion declines, popular folk religion and imported oriental cults become the religious lingua franca and are ultimately imported into Christianity.

My point though is that for the folk, as I understand it, the official cults of the city gods were always at best peripheral. And without an institution to locate them and the folk cults in one official theology or system or practices--the Greek city-state or the Christian Church, I'm not sure why we should count these folk beliefs and practices as part of the same religion as the cult of the city gods. Or why we should count Chinese folk "superstition" as a popular manifestation of Buddhism or some other "Great World Religion." And if we don't, we then have a religion that didn't evolve or develop according to your story.