i dont think they were really contemporaries. in the saga version, hyman roth appears as a teenager, while clem and vito are well in their adult life.
But it also showed that Roth was born in 1892 (he was celebrating his 67th birthday with all the mob guys on the balcony in Cuba in 1959). That means he was only one year younger than Vito.
And there we have another of those anomalies (like Vito's to birthdays). In a deleted scene from II, after Sr. Roberto makes his trembling exit from Vito's office, Clem introduces him to a kid who says he can fix their truck. Vito says they'll call him "Hyman Rothstein." In that scene, Vito looks about 30, Roth is about 17 or 18. But, in the Havana birthday scene, Roth's cake shows him celebrating his 67th birthday in December 1958, which gives him a birth year of 1891, same as Vito. That would be consistent with Frankie saying "your father did business with Hyman Roth," and Roth telling Michael how he and Vito "ran molasses into Canada," etc.
