Interesting! I never noticed the difference, I normally notice errors like speech, figures. o3o Anyways, my thoughts is that once Luna turned into Nightmare Moon, she needed minions. She transformed all of her army into Bat Ponies. *However they looked like stallions and pegasi, so Princess Celestia wouldn't notice her new powers so she can find a weakness and you know *cough* defeat her. ((I'm working on those parts ) Anyway... after that change, there was hardly many mares left due to Nightmare Moon turned most of them into her army, so Celestia recruited stallions, and it shortly later had an impact in recurition. Bassicallyy due to thats basically a story that I have work at, my theory is that there was a possibly shortage on mares, perhaps most of them were killed from a huge battle for example The Fall Of The Crystal Empire, or Nightmare Moon. So stallions were more in the army while mares ...got different jobs...?