The thing about "shooting to wound" is that the minute you pull your gun, you're legally considered to be using deadly force. Likewise whether you shoot him in the leg or center mass, you've still used deadly force on him.
If you are not in immediate fear of death or great bodily harm, then you have no legal authority to use deadly force, and shooting someone in the leg instead of center mass may suggest that you weren't actually in fear of imminent great bodily harm or death and had no legal right to use deadly force.
The police are required to use the least amount of force necessary to apprehend a suspect, the rest of us are required to refrain from using deadly force until we are put in reasonable fear of death or great bodily harm.
If you are not in immediate fear of death or great bodily harm, then you have no legal authority to use deadly force, and shooting someone in the leg instead of center mass may suggest that you weren't actually in fear of imminent great bodily harm or death and had no legal right to use deadly force.
The police are required to use the least amount of force necessary to apprehend a suspect, the rest of us are required to refrain from using deadly force until we are put in reasonable fear of death or great bodily harm.