Is augustine wrong to argue that humans have a distinct human nature?

Augustine's starting point for his account of the relationship between men and women is the story of the creation and Fall found in Genesis 2-3.

In Genesis 2: 18 God says  “It is not good for the man to be alone. I will make a helper suitable for him.”  From this Augustine concludes that Eve is made to be Adam's helper.  He further deduces that her primary role must be procreation as (in his view) a male companion would be better for every other task.  Better for physical labour (stronger) better for conversation (more in common).  

'If it were not the case that the woman was created to be man’s helper specifically for the production of children, then why would she have been created as a “helper”? Was it so that she might work the land with him? No . . . a male would have made a better assistant.  One can also posit that the reason for her creation as a helper had to do with the companionship she could provide for the man . . . .  Yet for company and conversation, how much more agreeable it is for two male friends to dwell together than for a man and a woman! . . .

radiant energy is a form of kinetic energy only.(a)