Thread:Wagwan piffting23/@comment-30706862-20190925133602/@comment-31129923-20190926000155

As stated by Wag, Bill could change his name, even without going through legal means, as other people had done in history before modern times. For example, real-life outlaw Butch Cassidy changed his name from Robert Leroy Parker.

On what Bill states in the game, while he says his name had been Marion, he changed it to Bill himself. Really not something that should be overly stated, as it is already noted in the "Background" and "Trivia" sections on his page.