The issue with sex cults is that in the reality tunnel most people live in, heterosexual sex involves women 'giving up' something to men, who are 'getting something'. Thus there is almost always a gender imbalance, as males will happily join but women are much less enthusiastic.
There are only three ways to make a sex cult work. Either it needs to be made up of exclusively rich men who hire whores, or it's some dumb bullshit where only the leader gets any, or it's primarily a gay/bisexual sex cult. The first two are grayfaced as fuck and the last one doesn't appeal much to be me personally.
Anyway, who says your cabal can't have sexy tomboys and femboys? For sure not me.