Of course the world they come from matters. There's a big difference between looking at Stark, Wanda, Romanov, Rhodey, Ant-Man etc in Civil War, and watching characters like Nakia and Okoye in BP. The former makes it feel like an Avengers piece with heroes from different walks coming together in a narrative. The latter is simply BP characters in a BP story. Your Raganork analogy is a good example of why that is not ever considered as feeling like an Avengers movie, while CW is. Thor dominates that movie, despite Hulk being in there in a supporting role. The cast are predominately of Thor's world. You keep citing the narrative structure of CW coming from Cap's actions. Again nobody disputed that. Its how that narrative weaves in so many major MCU heroes with their own arcs that makes it feel like Avengers 2.5, rather than a Cap movie.