I don't know if the girls are assigned classes based on same pattern or not, but it's fun to find patterns, even if they might not be real. So far, what I've noticed is:
Charm girls are usually the ones with/based on all sorts of kinks. In a way this makes sense I think, cuz you need trust for experimenting kinks and 'lover' sounds more trusty than 'expert' or 'shagger'. And their positions are all oral, and oral sex is a kink in itself(although it barely scraps 'kink').
Know-How girls, as I've noticed, are the more decent/shy ones in terms of nudity and kinks, as compared to hardcore. A smart man's choice I guess?
Hardcore girls usually are the hot sluts that wanna fuck and take full advantage of this worlds open-mindness. For once,following their class name, most hardcore girls do seem into the hard sort of stuff(Not the handcuff-whip dom stuff, that's a kink, and so you get Jennie there, who's cham.)
What do you say?