Theres no way Hyman Roth would name himself as Hyman Roth in 1918. Hyman Schowsky *sp only took Arnold Rothstein's name because how he admired when Arnold Rothstein was accused of fixing the 1919 World Series. During the scene when young Vito meets Hyman by Clemenza, Clemenza propose to name Hyman "Johnny Lips" (I think, correct me if Im wrong). After thinking, Vito thought a name for him and became famous with "Hyman Roth."

For the record off point after my prior research in the past about Arnold Rothstein... I believe Arnold Rothstein was innocent and had no parts for the scandal of 1919 World Series. Rothstein was famous for making large bets before that and people got out of hand by saying Rothstein started the bets for the World Series. If Rothstein wanted to fix the World Series or make a bet, he would have proudly said he did it but he repeately denied having a thing to do with it. Just few years later, he was shot dead after owning some gamblers large sum of money.