On the matter of all of them turning out female, first read THIS LINk - or at least enough to understand the reference.

Pterry has taken the basic quote, twisted the context, and then cut a significant part of the quote - maybe this time he was being too clever and assuming more knowledge than some readers have - I know the context of the quote because I had a couple of small parts in the play "Vivat Vivat Regina" which covers the history of that period, including that quote - I understood the reference immediately, saw what he was doing by truncating it, and therefore knew from the start that every real member of the unit was going to be female - the political officer masquerading as a corporal didn't count, and Blouse as the lately appointed officer didn't count.

Given that the joke as I saw it was that Blouse having been posted to the unit was so convinced that he could fool anyone when he was impersonating a woman, but was actually the only unsuccessful cross-dresser in the entire book, having Maladicta and/or Jackrum turn out to be male would have killed the entire joke for me.