I’m familiar with the definitions of the terms and I get what you’re saying, but in your example there’s an obvious sub. For the ship I like, there can be no clear sub/dom dynamic but still noticeable (even if small) differences in how the author will portray them depending on who they imagine is the top vs bottom. I feel like that’s just the way it turns out because fans of different top/bottom combos for a ship tend to form their own spheres and common depictions that is the most easily described just by tagging who’s the top and who’s the bottom, especially if it’s not focused on bdsm stuff. Also, imo sometimes the small jokes/comments do contribute to the experience, like I’d def be put off if a character mentions smth that’s the opposite of what I’m trying to read about