He's the Eddie Mannix character.
Yes, regardless of what Eddie Mannix was like in real life... he is the protagonist in the movie.
There was an interview my wife saw that said Brolin completely wrapped George Clooney’s “smart car” with cellophane during filming as a joke. Apparently, Clooney didn’t appreciate it much.
*** Spoiler Alert ***
In real life Mannix of course had multiple affairs, no kids and reported Mafia connections while in the movie he is portrayed as good family man. As I said previously there are a great deal of inside jokes to old movie lovers.