Mark, I only pen my feeders. Inside I have a spin feeder, sometimes a protein feeder, and a mineral block. I've been doing this for several years and I've never had a hog inside. I use hog panels, (32" high I think), a T post at each joint, and one in the middle of each panel. I chop my T posts off until they drive evenly to the top of the panel with the T post plate buried about 2"/3" deep. T posts on the inside of course.
They don't root in my plots, but they do eat a lot in them. My main gripe is that they root where I drive and where I mow. A large boar will make a crater a foot to 18" deep and three to five feet across. It is extremely aggravating to try to mow there. They also move deer around and affect how and when deer move. Deer will not stay on a plot if a hog comes around. They inhibit deer feeding in plots at night. I don't know how many pics I've had of deer feeding in my plots, all of a sudden their ears go up, and a minute or two later the plot full of deer becomes a plot full of hogs.
You can kill the hog if he shows up while you're hunting, but your deer hunt is over for that sit. That's why we kill every hog we see without exception.