The danger from safari guards with guns in my limited experience is more that they would fire in the wrong direction and hit someone. Ammunition is expensive enough that they don't practice much, if at all.
Hmmm, I guess that is not particularly reassuring. Let me try again.
There is plenty of food for animal predators in photo safari game parks. Evidently we humans simply do not taste very good and a predator would come after us only as a last resort. You will be safe, don't let that fear dispel you from the vacation of a lifetime.
Strongly suggest you consider Ngorogoro Crater in Tanzania. Most westerners have not heard of this locale but if I had to pick one location from the bunch that I have been to, that would be the one.