In the course of his reading, George Orwell probably encountered certain storytelling conventions over and over again, and these are the devices he would have most likely used in his work. That is why it does not follow that, even though his 1984 resembles other books of its futuristic genre, Orwell read those books; it is possible that he and the other authors were simply drawing on the same body of literary conventions.
To direct an effective movie within the cowboy genre, a director must study previously successful cowboy movies most closely illustrates the principle that the passage illustrates.