Good point
That may become the subject of my next Torah study: when did tribal monotheism become universal? As a guess, I'd say sometime after Joshua and before Solomon.
The problem, of course, is the difference between internal chronology and external. Despite the legend that all of Torah was dictated to Moses on Sinai, the first four books weren't compiled, codified and redacted until Solomon's time, by Bloom's proposed "J" and others. There's an awful lot of later editorializing written into stories of prior events, not always clear to an amateur like me.
But you have me curious...