Human sacrifice and expansion was the answer because the Aztecs were a feared tribe and conquered many people. They had always practiced human sacrifice and that was one of the reasons that Hernan Cortes had been horrified about. It couldn't have been anything about conquering Mayans because their civilization had died out for some strange reason.
During WW2 about 350,000 women had joined the military with many having medical roles as nurses and many also helped to drive trucks to transport certain supplies or munitions to the front.