The text states in several places there is a meaningful gender difference:
"Welcome to a world where men are mighty, women are voluptuous..." (page 4)
"a world of cruel kings, barbarous fighters, beautiful but seductive women..." (page 4)
"Female Mazanians are all stunningly beautiful, since all girls with the slightest physical flaw are quickly abandoned in the jungle." (page 15)
But you studiously avoid even hinting at any mechanical framework to support any of it
My personal observation is that since your game is already targeting a mature audience, it should be able to expect players to meaningfully handle gender differences, as opposed to the current inclusive trend. Don't get me wrong, I like equality in the real world. And I love the stereotype of the 4"10' lithe girl who busts heads as much as the next guy, but S&S is decidedly not a Luc Besson arena
Just as a brutally simplistic example, if the rules should offer "males get +2 to Strength, females get +2 to Charisma", even as an optional suggestion, most players will be nudged to playing "genre-appropriate" characters, that is, most hulking brutes will be male while most bewitching enchantresses will be female.
Note: You still can play a female warrior based on Strength. You can still play a male
Bard Courtier based on Charisma. After all, there are no penalties.
But since 5E already offers robust support for the "Dex build", you are likely to end up with a bad-ass woman warrior that looks like Grace Jones or Sandahl Bergman, and not a gender-switched Arnold Schwarzenegger or Sven-Ole Thorsen (the bad guy with the ridoncolous hammer). Which is the point. The only point.