If you're looking for something other than the worst possible thing, I'm afraid you're asking the wrong man.

[Tyrion glances back at the smoking wreck of the caravan, a twisted puzzle with no good answers.]

I can only think of one reason for them to only take the women, and leave the girls who are too young to have bled yet. What I want to know is if they did this on their own initiative, or if they were working for someone else.