To be honest, this just sounds like you're dealing with generalisations, and calling them "essences", rather than actually proposing any sort of essentialist model of social dynamics. Unless I'm misunderstanding?
Essences as I use it can be understood to be generalizations based on what generally makes a group of social institutions distinct to other groups. So it is a special kind of generalizations.
How do you defined the "supernatural", in this case? I'm guessing that it's something more precise than simply upholding the existence of a spiritual dimension to existence, otherwise you'd have to lump Platonism or Cartesianism in as "religion".
Also, what is meant by "assumptions"? Not all religious systems are just based on a hodge-podge of old customs- Buddhism would be only the most obvious example of a religious system which has been historically defined by a concious development on the part of its practitioners- so, again, I'm assuming something more precise?
The main problematic here seems to be that what we today view as supernatural was as an idea very natural to Plato.
I am not sure how to exactly define supernatural to be honest

I said early that the definition of religion probably also requires a certain type of implementation (which I expressed by "development" and "organization"), which could ease this problem.
As to assumptions - I explicitly removed the attribute dogmatic so to give room to conscious change.
Now as long as Buddhism stays with its aim of "enlightenment" and as long as this state of being is treated as something supernatural rather than just people using specific techniques to mess with their brain, I don't care how that status is supposed to be reached.
So if some modern Western guy embraces teachings of Buddhism, but without actually having faith in the so-called nirvana, I wouldn't say he is religious but just someone who embraces specific techniques of a religion.
Do you have any reason to believe that the process unfolds in quite this manner?
Not more than my thoughts.
First and foremost, it doesn't take into account the animistic belief-system which "primitive" peoples, for want of a better word, almost universally possess, which from what I understand is believed to precede any particular mythology.
I find it really hard to imagine how a group of people started to adhere to holy wolf spirits or whatever without predating stories which transformed into such believes.
I mean how is that supposed to have happened?
"Guys, I really think those wolfs have some kind of spirit."
"I am glad I am not the only one! Let's spread the message! But wait, what
is a spirit?"
"Erm.. I have some great idea for that, too!"
Meaning, I find it hard to imagine how religion was invented consciously rather then naturally. And by naturally I mean it is the natural product of another process - and that IMO can only be stories and their further development. What else could it be? But keep in mind that by stories I don't necessarily mean a specific mythology. I just mean people talking about their experiences and emotions and putting them into the context of what they were told by their parents and so on and how such narratives developed over time.