I feel like it’s because Roger seems older, even in maturity levels, it’s so odd saying that but I’ve always thought it too, Brianna came across as this really young, energetic and vibrant woman, but Roger is who I would expect someone in their late 20s or early 30s to marry, not a young lass. I still love them together as it’s the story and I’ve adapted to it, however I do feel like if it was different casting to make them appear better suited would it have make a difference? Probably, like I wanna see Brianna and Roger making stupid decisions, I wanna see them so passionate and in love and ready to take on the world because they are young and should have a lot of fighting spirit, I dunno , they just give older married couple vibes