As I read the Noevl and watch the movie I have come to the Conclusion on something.

In the Novel, During the Mob war after Sollozzo's murder and McClusky's killing I think the Corleones were attacked only by both the Tattaglia's and Barzini Families. It said Cuneo lived far upstate New York with his operations. Stracci lives further in the state of New Jersey along with his operations. I figured they wouldn't want to get mixed up in the war in the 5 Boroughs of NYC since they are such a distance as the Novel put it, even though Stracci was confirmed to be against the Corleones decision on Drugs. I don't think they would risk their Families in the war like I said before. Why else do ya think Mike didn't have them killed along with Barzini and Tattaglia as well as Fabrizio?

In the Movie I think all of NY Families teamed up against the Corloenes since they live so close together in the 5 Borroughs in NYC. The Movie made it different from the Novel. Cuneo lived in the Bx, Stracci from Staten island, Tattalgia from BK, Barzini is a good question. And that's why Mike had all 4 men killed together during the baptism. Because all 4 Families supported Sollozzo.

Just thought I should say this. Let me know your take on this