I think you are over-analyzing this story.You are all breaking this down too much. Perhaps I am wrong but the author's work didn't feel like it had the intent of necessarily changing the already established narratives and world building of the omegaverse genre (trope?) but rather to portray theyre kink. If you read there other manga, kinpatsu wa shinshi, this author has a slight attraction to having bigger or more typical "seme-like" individuals bottom for a more uke-like dude.
I think you are over-analyzing this story.You are all breaking this down too much. Perhaps I am wrong but the author's work didn't feel like it had the intent of necessarily changing the already established narratives and world building of the omegaverse genre (trope?) but rather to portray theyre kink. If you read there other manga, kinpatsu wa shinshi, this author has a slight attraction to having bigger or more typical "seme-like" individuals bottom for a more uke-like dude.