You may have dozens of guns and be an excellent shot, but you won't be able to watch all of your property all of the time, or even a fraction of the time. People are going to walk through there.
Also, when you shoot Cletus for walking across your land, thanks to the inevitable police report and contacting of kin, his brother Bocephus now knows where your property is.
You have to exercise good judgment. As long as they aren't hurting anything or squatting, turn a blind eye. I know, because I have parcels in NF.