After that bit was spoiled to me before reading it, I had expected MR to be a lot sillier, though. All in all, it was, despite the sillyness of a joke stretched the farest possible way, one of his darker novels. The single characters, all taken one by one, all worked for me - all had convincing reasons, except for Maladicta maybe...
(Sorry all for repeating myself a little here by the way. )

In the frame set as it was, I somehow had no problems with Jackrum turning out to be a woman, or a third of the military elite, at that. Interestingly (for myself), the mental image of Jackrum didn't change the least.
And as said, it was, in a way, only consequent. Consequently over the top, but well - there are so many, serious as well as silly, attempts to the Gender-switch-story, maybe Pterry pushed it until it became absurd because he didn't want this DW novel to be another one.
Stretching an idea popular in literature until its extreme is -or at least used to be- part of Discworld (as well as is then giving it yet [i:ba587cb3d2]another [/i:ba587cb3d2]twist and take it serious again, once you've long crossed and left behind the sillyness-line...).

Can anyone still follow me...?

I also found it had a nice touch that of all, Jade and Igorina were the "girliest girls". ("...mentally ordering a big pretzel when looking at her...") And the whole concept of the way you live and the cultural practice you exercise changing your identity and not necessarily the other way round...