Emily,
I am certain that they are all somehow related and I have the same problem fitting the pieces together.
I do know of Nicolas, Vito, Giacomo, & Pietro Impastato of Cinisi, who eventually wound up in Springfield Illinois.
I was married to Vito's son, Faro Vito Joseph Impastato and have his daughter Vithina Teresa Catharina Impastato.
They are all deceased,except my daughter, but I can tell you that they had more relatives in Cinisi who died of disease at early ages. Teresa and Catharina were twin sisters of the Impastato brothers who died as babies from some disease and their Mother died giving birth to them. Their Father was a butcher in Cinisi and I am not sure what else he did. He died of a heart attack awhile after WWII.
There are stories that there were Impastato's who were cattle & sheep ranchers in that area as well.
It is my understanding that they fled because of Mussolini and Hitlers' tyrannical regimes.
The closest living relatives of them live in Baton Rouge LA., and Metaire, LA.
There are people in Cinisi who can be contacted for more information.. It is a very tiny village and much folklore abounds over there, so take it for what it is worth to you.