I always saw it as Vito,wanting to get through everybody on the list as quick as possible,so he could then go and enjoy his daughters wedding.The tone in Vito's voice,seems to sound impatient,rather than fear.
VITO CORLEONE
I want you to go tonight; I want you to talk to this -- movie bigshot, and settle this business
for Johnny. Now, if there's nothing else, I'd like to go to my daughter's wedding.