So lets talk speculatively here... because really at best only half what I say actually ends up to be completely true. I guess my thoughts pretty often differ from my words and then they also tend to change when I actually start to work on something... Well whatever, words can't convey truth anyway.
Careful approach is the best one when working on game design and it's a hardest one as well, because you just spend tons of time without doing anything but trying to plan it out and find ideal balance considering truckloads of problems. For example, my fighting system is something I'm relatively satisfied with. It's not top shape right now, but I believe it won't have to be changed in any major way - it's easy to grasp, has enough hidden complexity and somewhat satisfying. And for text based game I consider it sort of achievement.
Now I wouldn't say that I want to spend whole next version on reworking of prisoner's system if I had very vague ideas on it. Most problems come with what exactly I want from it.
1. Girls should feel unique. 2. Girls quality should progress as game progress. Partly this is satisfied by multiple different races. But the bigger aspect is - personality. And here's the problem. Can't really give distinguishing personality to procedurally generated characters. At some point player just understands most of the mechanics and it becomes very simple picture.
I considered multiple solutions and in the end I believe the final solution will be a mix of them. Firstly there will be 1 core stat - Character(temper). It will range from a 'pushover' to 'heroine' which player will be able to observe at any point. Idea is pretty simple - the lower it is, the faster girl will be broken. Now though, breaking strong-willed girls can occur in different ways. Normal ways which will be available early game will still work, but they will damage her personality in process, reducing her character, maximum available skills, strong points of her personality and so on. This will suffice 2 purposes. 1 - you will still be able to employ a strong-willed girl early in the game 2. - fun of breaking such girls. Second option won't break her character but will take some expensive resources, strong magic and so on.
Now there's completely different problem at my hands which translates - current system suck ass. Well not entirely, but it limits my options when adding girls, who are not humanoid enough or unsuited for every occupation. I have considered adding '3rd' group which would take such girls to behave as pets and cattle, but whole idea is kinda in the air right now. I'll think up a good way to settle all these parts, but it's pretty safe to assume old prisoner system will change completely.
Lastly, as I think new girls, who left prison, will be subjected to misbehave I also gonna work on a punishment system. This will likely be tightly tied to new breaking system and work on autonomous mechanic.
Warm reminder that I could use a help of writer or two as sex scenes are still not quite there yet.