I agree. Fanucci could murder if need be and his instincts were probably keen. Also, I think that it was characteristic of Vito to plan things out elaborately and to anticipate variables. He was smart too, enough so that (in the novel) he didn't take the $5 gold piece from Fanucci's wallet. Michael inherited some of those characteristics.

"Generosity. That was my first mistake."
"Experience must be our only guide; reason may mislead us."
"Instagram is Twitter for people who can't read."