Surely they patrol in pairs.
AND are truly/ appropriately armed with more than just 9 mm side arms.
It doesn’t matter if they patrol in pairs; on a dark or moonless night in the middle of nowhere locating the source of the gunfire can be very difficult. When I was a missile launch officer I had a two-man team guarding a minuteman site that had sensor problems. One called me up in the launch control center in the middle of the night, very frantic, and told me that someone was shooting at them but they could not see where the firing was coming from. It was all that I could do to keep him and his partner from randomly returning fire at a target they could not see. After I got them calmed down and got the response teams and local sheriffs out to the site they found a drunken North Dakota cowboy on a hillside in some brush who thought that it would be fun to scare the airmen guarding the site. He didn’t think it was so much fun when he had a dozen M-16s pointed at his head and a boot on his back. He was lucky that they couldn’t see him in dark night on that featurless hill because they might have gotten lucky and hit him but worse they might have shot at a truck or car coming down the county road. It might have been on purpose or it might have been benign, some idiot out hunting possum, racoons or some other wildlife. You can’t always see who is shooting at you and if you can’t see them then shooting into the blackness can highlight you and get you killed or some innocent person who might be in the area.