There are plenty of creators (writers, directors, composers, etc) who end up creating work within a existing universe. Think making Star Wars movies, or writing a Star Trek novel. Often the desire for the creator to put their own stamp on the work bumps up against the “rules” and history of the universe. But how should you approach creating something in a universe that already has rules and history?
One of the common themes of reviews of Greyhound is the lack of character development. This contains potential spoilers while describing a different perspective on the characters in the film.