To build off this point using the Alien franchise, the source material can be very inconsistent. As a specific example, Ripley's rank from Aliens to Alien Resurrection. In Aliens, she joins the Sulaco's mission as a civilian advisor, someone the military takes along but only listens to at their discretion. She had no authority whatsoever, which makes sense as she was just a bureaucrat and manual labourer that may have some useful information to that particular mission. She even explicitly states she isn't a soldier. When Lieutenant Gorman is incapacitated along with Sergeant Apone, Ripley points out that it's a military operation and Corporal Hicks is next in the chain of command. He only listens to her of his own volition. As a Corporal, he was under no obligation to do so.Ezekiel said:I do. There's too much profit involved for the content creators to decide. They will always expand their IPs, even if their decisions don't make any sense. So I have to decide what's true and what's not using the information presented to me.
Come Alien 3, which has a lot of canonical issues such as how the egg got into the cryochambers, the computer from the escape vehicle lists her as Lieutenant Ripley. She apparently had the same official authority as Gorman who was in charge of the whole crew, but his experience would have him ranked as Second Lieutenant which Ripley could not have possibly exceeded. There is no reason the computer would state that and is only possible through the writers misunderstanding the events and military structure of Aliens. Then in Alien Resurrection, she's Lieutenant First Class Ripley, now outranking Gorman and therefore being solely in charge of the Sulaco's mission as there was no Captain present.
So there you have it. According to the people in charge of the story not understanding their own canon and terminology, Ripley was upgraded twice after the events occurred. If one accepts the entire Quadrilogy as canon, you accept the contradictory view that Ripley was both civilian advisor with no authority and the highest-ranking member present solely in charge of the mission.