High Noon was a tale crafted about Hollywood's persecution of communists in cinema. Gary Cooper represented the ethical, good hearted communist being outgunned by the McCarthy types.
Rio Bravo was made in response to High Noon. Rio Bravo depicted the good guys (those who were fighting communism) against the evildoers in Hollywood.
I used to like Gary Cooper until I read about what a philanderer he was and how he used to beat his mistress, Patricia Neal. (Also a favorite actress of mine.)
Rio Bravo was a remake of El Dorado
Ooops...other way around. El Dorado was a remake of Rio Bravo
Rio Bravo was a blatant attempt to curry favor with a new audience by using Dean Martin and Ricky Nelson