Jill and Bella was meant to be an example of an unlikely, but not impossible, trio whose premises are all in two lines of dialogue
how long does it take to create the same premise for Sage and Jill? a couple of chapters and a few clues and special situations can easily be created.
Highly improbable but not impossible.
no more impossible than the fact that two girls you've had sex with are actually a couple who decide to enter into a lasting 3-way relationship....
no more impossible than that by dint of harassing a married woman she asks you out on a date (hentai logic)
one chance in a million, but one is there
Sure there’s always a chance, personally I’ll consider it impossible until it happens. I mean the game of course has plenty of porn logic woven into it in order to work.
(The MC has a giant cock, perfect abs, and can successfully seduce any target he sets his eyes on if he does the right thing. In addition he’s the second coming of Bruce Lee and makes money from puzzles on his phone).
I also gets the sense that DPC wants his writing to be taken seriously, and that he has at least to my mind, gone out of his way to make the LI paths be somewhat credible.
Add to this that the full on DIK path already gives you all of those things in droves.
But if we ever get that scene I hope Sage will be like : Hmm this Jillybean tastes like fucking vanilla, hey Fuckface, pour some whisky on her pussy, and maaaybe I’ll give you a 4 out of 5” * Quick zoom in on Jill covering her mouth while she lets out an “Oh my” .