I am not following your last statement.
Of total US hunters going to Africa each year, I have no doubt the vast majority or headed to SA. Namibia likely runs second. It is safe, easy and predictable. The hunter, and often friends or family, can do anything from boutique hotel-like lodge to a replicated East African field experience (but with ensuite facilities
) and everything between. I think the vast majority of those outfitters deliver what they promise. There likely is vast room for interpretation when terms like "authentic" African experience get tossed about.
I have no idea percentages of European hunters going to more challenging destinations, but I would guess it is likely much higher (total numbers probably would be a different thing). I suspect that this may have something to do with traditional European interest in "adventure tourism" and general familiarity and comfort with international travel. I do know that my Mozambique friends guide more Europeans in recent years than Americans.