Don Zalucchi was the Don of Detroit, and a thinly veiled Joe Zerilli of the the Zerilli/Tacco clan.

My take on the issue having read the books is that the Corleones were above the five other (Italian) families, including one not named - the Corleones alone controlled most of the political/legal scene - in addition to Unions and Gambling (which are the best things to have)

But if we need a real life fifth family or gang in addition to the standard four plus Corleone why not the Roth-Green-Lakeville Road-combine that fills in for the real life Lansky-Siegel-Dalitz (along with the Mayfield road gang)

This is the historical period were Jewish mobsters were transitioning either into legitimate business or the grave - but still held some power in New York and Chicago and points in between.

Jews would not sit in on a modern day commission meeting of book and movie, but would certainly be a force to be considered, and were so in both GF and GFII.

It is unlikely most Italians would use the familia styling, but Lepke Buchalter had a seat on the commission before his demise.