Why recruit normal people when they can do it themselves?

I haven't finished watching this movie, but if they have the manpower and the capability to hide evidence, why try to get normal people to do their deeds? Especially running out in public and pushing a guy's car off a rooftop, or chasing Nicholas through a busy street with a gun, even shooting at him. In real life there will always be witnesses who will call the police to report what they saw in the middle of broad daylight.

What I would have done was call the FBI when he asked me to kill the reporter. Then fake the death of the reporter, and when Simon contacts Nicholas again you can run a trace while Nicholas and his wife leave the city and find another job elsewhere.