Coetzer didn't have the firepower to take out Foreman in my opinion. But I also think '74 Foreman was more vulnerable to the incoming fire than 80's Foreman. Coetzer's other problem is that he wasn't too difficult to hit. Great chin, but then, he'd have to have. Old man Foreman was deliberate and really picked his shots quite well against Coetzer. Younger Foreman might bundle him out earlier but he'd eat a bunch himself.
In 2-4 rounds, Coetzer didn’t have he defence to hold up to that sort of power, especially in the volume young Foreman would be throwing, he’d close of the ring better and be coming with punches from all angles.