Yeah man.. Humans will be their no.1 enemy. Those are savages and tribes, they will see the women, and come back with their spears. Human history is full of wars and horror. can only imagine what cavemen were like. Seeing them now is bad. Just think zulus from Africa. Feels like they are fucked on their own, and fucked seeking out humans. Situation they are in now is fucked. 7 or so people in the group to feed. So they have to be active.
The other thing to worry about... is theres always at least 1 person in the group who will go crazy. Always happens in these stories of survival.