Uh, Wikipedia? Really?
The term "extra" isn't even an official term used in the industry. I assure you that people like "You mess with Spidey, you mess with New York!" guy are seen as and referred to as extras within the business.
Completely and utter bunk - until it got merged into SAG, they even had their own union called the Screen Extras Guild. Although the term 'background player' is now standard.
As for the fact that you think that 'extras' cover a range of roles - Albert (2008) notes that the difference between an extra and day player is the day player gets a line and is therefore bumped to a higher rate. Above that is the 'under-5' who is someone who gets five lines or less. Hollywood Unknowns: A History of Extras, Bit Players, and Stand-Ins
by Slide (2012) indicates the same categories.
More specifically if we look at the trade literature of the time
such as Billboard, they use the same distinctions when discussing pay and condition changes.
That Sulu and others were extras in the sense you use the word is nonsense.