I think you nailed it. I believe the Greeks also feared the Spartans because of Spartan women.

As you pointed out, women were a big part of WWII and haven't looked back since. The U.S. Navy is 21% women. There are very few women in the Russian military and none in the Chinese Navy.

If women are included you double your chances of getting good people. Even Japan has gotten on board. Physically, women are no match for men. IMO. Yet most famous war heroes I remember were runts. Brains matter. IMO.