Nothing you ever read about Glorantha is true. Everything is speculation
done from eleventy gazillion miles away and umpty-whoo gazillion years
apart. Treat all "canon" like this multiplicatively so. Get the book
"Motel of the Mysteries" and read it well (it's very short and funny, so
it won't be odious). Learn what it teaches about reconstruction of
societies from fragmentary evidence.
That is what Glorantha is--a reconstruction from fragmentary evidence.