What is your point? It was a movie, yes. The director was impressed with Bonnie and Clyde. Vis a vis the story, given that one Corleone had already shown an irritating ability to survive assassination, I think Barzini wanted to make sure it would not be repeated..

"When the snows fall and the white winds blow, the lone wolf dies but the pack survives."
Winter is Coming

Now this is the Law of the Jungle—as old and as true as the sky; And the wolf that shall keep it may prosper, but the wolf that shall break it must die.
As the creeper that girdles the tree-trunk, the Law runneth forward and back; For the strength of the Pack is the Wolf, and the strength of the Wolf is the Pack.