Thoughts on petroglyphs as seen by a crafter of images

We were in awe of the petroglyphs on a trail just off the main one to Delicate Arch in Arches National Park near Moab. The horse riders and sheep are clearly recognizable. We questioned why the sheep horns didn't curl all the way around or was this an extinct animal we were looking at. The horses indicated a recent petroglyph ruling out the likelihood of extinction. I would venture to make several observations based on my experience crafting images on different surfaces with a variety of tool. First, the petroglyphs are images made in accordance with the properties of the cutting tool and the resistance of the rock surface. In order to depict circular curved horns it would require continually readjusting the angle of the cutting tool. Second, making the horns completely circular violates principals of making the most recognizable image with the simplest of means. Third, the addition of the circular design pulls attention to itself like a bulls eye and the importance of the animal body is diminished. Looking at petroglyphs on the side of the Potach Road