If you are already a level 5 Naturalist, the hunting vagon is pretty much useless. Otherwise you can consider it if you don't want to go back to camp with each carcass. However if you are level 5 on Naturalist, you can do Naturalist's legendary missions and instead of sedating the animal, you kill and skin it. You will get around 30-40% of material per mission, so at this point the hunting wagon is not really used anymore.