Why should we expect there's one underlying way that economies work? Because economists of all stripes use the word "economy," just as biologists speak of "species" in general, not just of certain fish, birds, or insects. Biologists have a theory of species, and physicists have a theory of matter (not just of solids, gasses, and liquids), so economists should have a theory of economies.

Economists claim they're doing science, which means they ought to have a sophisticated general idea of what they're talking about.

You've now conceded that they lack such a thing. And I've given my hypothesis to explain that peculiar fact (the hypothesis being that economics is more like the perpetuation of political propaganda than the doing of science). I never claimed my account is necessarily true. Of course it's just a hypothesis.