My experience in RSA is that hunting is more about walking than clambering over and around obstacles. The walking can be hard, uphill or downhill, or along a hill, or along a valley. Always through thorns mind you. But it is all walking. By comparison, when I hunt northern Ontario it is much more challenging terrain with obstacles such as logs, rocks, marsh etc. Very few thorns. My boots for home require much more support than when I am in South Africa.
My suggestion is pick a boot that allows you to walk. Don't fret that you will do much challenging terrain.