Not so sure about the muscle idea. Though it works in many situations for intimidation factor and pure power if it comes to it, most folks who encounter the muscle man will simply get some muscle of their own. Or just take him out from a distance. This is the age of guns after all. From personal experience the muscle guy better have some training (and probably weapons) to back it up, else he just makes a much bigger corpse when the stuff really hits the fan.
Hiring muscle has its benefits but it is far from a cure all for personal protection.
Just my 2 cents.