I think it's great that Puzo and Coppola don't really show how hardcore the top Corleone Enforcers are. In fact, the irony of it was they are always elluded to, in terms of their abilities, but never really given a chance to shine. For instance Luca Brasi, was quite possibly the most fear enforcer in the Godfather universe, but he is killed in the bar scene in GF I.

Al Neri, for those of who read the book, was like Luca Brasi #2. He was in GF I, killed Barzini by dressing up as a cop. Always in the background of GF II and in GF III. But he has such a minor role as en enforcer it's outstanding although his abilities were elluded to in the book.

Finally the hitman in GF II, who accompanys Michael to Havana is hardcore looking but meets with a timely death.

Now, not so much Neri, but Brazi and the Hitman from GF II are pretty much two of the most intimidating characters but both are punked off without an elaboration or visulatization of their abilities. Was it Coppola and Puzo's intention to just have their reputations preceed them or was there another point?