Agreed- the unofficial leaders of the Italian and Jewish syndicates at one time. I'd add in Costello and Siegel, even though the thread asks for 2.

They were closely aligned and were connected in many high profile rackets and major events: Ending the Castallamarese War, Havana gambling, organizing the mob meetings in Atlantic City and Havana, the Flamingo, WWII, high level political connections, Murder Inc, the set up of Genovese, the possible whistleblowers for Apalachin, developing drug routes, Louisiana slots, Hollywood, etc...