Possible Clues:

• Either 'The Ballad of Buster Scruggs' filmmaker
• Name on many posters with McDormand and Buscemi
• Surname that's an anagram of an orange traffic item
• Either ''Hail, Caesar!'' director
• Surname on a 2010 "True Grit" poster
• Ethan or Joel of filmmaking
• Last name of filmmakers Joel and Ethan
• See 44 Down
• Last name of filmmakers Ethan and Joel
• Last name of both "Fargo" writers