That is not a full-time job. If Oog decides he's going to spend 10 hours a day doing nothing but make stone axes for the 15 other men in the tribe, Oog is going to have a bad time.

In a hunter-gatherer context, the men are hunting, fishing and fighting, while the women forage and manage the children.

You're missing the point. There's a fundamental difference between doing what you're good at for the benefit of the tribe and doing what you're good at for your own personal benefit, refusing to share with the tribe unless they agree to your terms.

The former is sharing, the latter is trading. And again, there's no evidence that trading ever occurred in that situation. As another commenter mentioned, in the life-or-death scarcity of hunter-gatherer communities, you'd be punished or exiled (which would mean death) for modern capitalist-style selfishness. There's no commodification.

Also, knowledge and skills were shared. There were no trade secrets, no patents. It would be have been extremely dangerous for one person to be the exclusive source of an essential good. Again, specialization is a luxury of abundance.