A long, long time ago, there was a game called Final Fight and a character named Poison, who recently showed up again thanks to Street Fighter X Tekken. When Capcom was developing the character for the original Final Fight in Japan, she was always intended to be female. However, they were worried about how American audiences would respond to hitting women and wondered if feminist groups would sue.
"Hitting women was considered rude," according to All About Capcom Head to Head Fighting Games. So the character was made a transvestite. Playtesters for the SNES did indeed express dislike of hitting girls, and the explanation that Poison was secretly a dude was not exactly met with the greatest of enthusiasm. She was replaced with a male character named Sid.
With the exception of fighting games, which have always been oddly very equal-opportunity, it's remained fairly rare to see female minions in the wave of enemies. If they are present, they're almost always some form of dominatrix. Regular shock troops in the rank and file? Not so much.