In my playing and modding, it always seems that Monotheism and its benefits follow Polytheism too quickly. So I dug away at vague recollections and secondary and primary sources (clergy) and came up with the intermediate step:
MONOLATRISM
"Monolatry" is the belief in one god being supreme over others, and actually represents Judaism (so I am told) historically through the writing of the Book of Deuteronomy ("Thou shalt have no other God before me"; etc.).
Beyond using it as a place-holder tech between Polytheism and Monotheism, I stick the "Great Temple" (doubling the effect of Temples) in that slot. It seems to work quite nicely.
... And if anyone actually uses this in a mod, I expect a footnote.
Your Not So Humble Researcher,
Oz
MONOLATRISM
"Monolatry" is the belief in one god being supreme over others, and actually represents Judaism (so I am told) historically through the writing of the Book of Deuteronomy ("Thou shalt have no other God before me"; etc.).
Beyond using it as a place-holder tech between Polytheism and Monotheism, I stick the "Great Temple" (doubling the effect of Temples) in that slot. It seems to work quite nicely.
... And if anyone actually uses this in a mod, I expect a footnote.

Your Not So Humble Researcher,
Oz