Hunting and foraging can be unreliable and definitely is to a modern human. Early humans hunted in packs which made them the most successful predators. They didn't have the stamina of a cheetah or the strength of a lion, but they could withstand the elements and chase and stalk their prey for days until it became exhausted. They could also mount very intricate surprise attacks. Overall, I think there was a heck of a lot of ingenuity that stemmed from the pack nature of these hunts and I think we'd be giving these ancient guys a bad rep if we didn't acknowledge it to some extent.