Tbh Priscilla is a hot MILF and stuff but I hardly see any positive outcome for her in the story... She's on death row already, she'll get one scene at best or maybe a tiny epilogue should you manage to keep her alive, but she's not central to the story.
On the other hand, there might be a way to close the western civil war arc quite easily if you consider it like a sort of mini-game where you just close the arc, win support from a side and get a specific bonus perk (i.e. Da Western Noble Army Joins Ya Forces Your Army is Now Size Big), set some flags for future lore shit (The Elves: Upset +1000), get a specific side-girl winning scene, and voilà your plot doesn't devolve into 16 different paths.
All in all i'm pretty sure this game will only ever have 3 branches and extra scenes depending on which LI you're romancing.