As a neutral American (it still mystifies me how Man United
continuously loses to West Ham, regardless of ranking), I find this whole argument to be hilarious: two of my best friends are West Ham fans because Elijah Wood was in
Green Street Hooligans.
http://www.imdb.com/title/tt0385002/
My firm opinion? Since Frodo has already run off to do a film about his favorite football team, perhaps Boromir should do the same. Regardless of artistic licence... though Boromir standing atop the battlements of Osgiliath dressed in the Sheffield colours is an entertaining thought.