And as to the pioneers of pulp fantasy:

One time, it is reported,
one of Talbot Mundy's Jimgrim books,
The Devil's Guard (1926),

fell into the hands of Marion Zimmer Bradley,
at the time deep into her Darkover series.
And she looked at the book's premise, and thought:
What if I redid this exact story,
replacing all the men with women?

The result was City of Sorcery (1984).