The most factual errors I can count on film, well maybe
I understand that "Mobsters" isn't a historical-biography, with that out of the way, this movie is loaded with so many errors is actual a let-down.
First off, it's Salvatore MARANZANO, not FARANZANO.
Secondly, Joe Profaci wasn't a frumpy old fat womanizer, he was an average male who wore glasses and was a devout Catholic who often pressed his own men for too much of a cut for his own pocket
Third, Tommy Reina was killed by Vito Genovese ( future head of the Luciano-Costello Family, now named the Genovese) with a shotgun blast to the head in the streets. Not by Bugsy Siegel with "Mussolini's Stolen Pistol" in a sauna.
Fourth, Lucky Luciano met Meyer Lansky in a fight between them during their youth, with Luciano winning but being impressed by Lansky never backing down. It was not Vince "Mad Dog" Coll who beat Lansky.
Fifth, Joe The Boss Masseria was killed in a Coney Island restaurant after playing cards and eating a huge meal with Luciano, upon Luciano excusing himself to go to the bathroom. Masseria was gunned down Bugsy Siegel, Joe Adonis, Vito Genovese, and Albert Anastasia. Not by Siegel and Costello.
Sixth, the entire finale is completely fictional. Mad Dog never killed Luciano's mistress and Luciano never killed Mad Dog. Maranzano ordered Mad Dog to kill Luciano but was murdered by 4 hired gunmen (Not Siegel,Lansky,Costello and Luciano). After Maranzano's murder, Mad Dog was met by the 4 gunmen and paid to walk away, which he did.
The facts in this movie are horribly twisted.