It depends on how you define 'real'. Copacabana might have been influenced by real events, but it could also have significant fictional components added for entertainment purposes.
Typically, the decisions about who lives, who dies, and who tells the story in an animatic are made by the team of writers and animators. They consider various factors such as character arcs, the overall theme, and the intended impact on the audience.
Disney is the cartoon king because of its consistent innovation in animation techniques, the ability to create timeless stories, and the wide reach and popularity of its franchises. They have set high standards in the cartoon industry and continue to inspire others.