Okay, let's cheat a little and say that one or two of these are similar to wheat/barley in the Fertile Crescent... big seeded, easy to domesticate... basically, worth the effort to leave hunting/gathering and take up farming. If we can get this happening roughly the same time as agriculture started in the Middle East, SA can make it in the civilization game. However, I'd think they are going to be slowed down compared to other places... they have a crop plant, but still don't have any domestic animals until later on (when outsiders bring them). Plus, from what someone was saying on here earlier, it seems that the ingredients for a copper/bronze age are kinda scattered around, so the metal/tool age may take somewhat longer. Still, it's a doable scenario...