I don't think that's necessarily true. Whenever one creates content aimed at a particular audience, the main character usually reflects the target demographic. Remember Madness Together started with David. And I'm not talking about page one of Chapter one of
VIP Madness: Together. It started with David in Chapter Six of
Satisfying Needs. So David was always the main character since the events of
Satisfying Needs Chapter Six is what led to his sudden behavior at the start of Madness Together. While it was slated to be neither a harem like
Satisfying Needs nor a pseudo-romantic pornographic soap-opera like
Immoral Desires, from what I can tell, Madness Together was going to be an incest free-for-all between the characters at Sarah's house, with a planned late appearance from Sarah's father.
It only appears to be about Sarah because of the folly in Daval's manner in which he had introduced Uncle Peter. And this is typically the issue with "female-led" harems, that is, the predominantly male audience doesn't care about the female characters' needs or sexual pleasure in and of themselves;
only how that pursuit of sexual satisfaction leads to the main male character's sexual fulfillment, the character with whom they identify. The problem with Madness is that a lot fewer members identify with Peter than they do David, which is understandable considering that the first three chapters featured David. So it would stand to reason that the audience garnered through the initial success of Madness Together would align with David, and not the "old ugly bastard uncle" archetype of Peter's character. And while your guess is as good as mine, I think Sarah, if you ask me, will probably have sex with her son and maybe just her father by the series end. Just from what I've gleaned, I think those are the only two male characters, in addition to her husband Luke, with whom Sarah can have sex that won't completely alienate the David-fans given that the previously mentioned male characters are her immediate family members.
Daval is clearly attached to Uncle Peter, which explains his upcoming spin-off. And... (to prevent some fans from reliving the events of Chapters Four through Six):
