You misunderstand the biological component argument, I think. It's not that men are massively more suited to some jobs and women are massively more suited to some jobs. It's that for some abilities the the center of the wide bell curve for men is not at the same place as the center of the wide bell curve for women.

For example, for verbal abilities the female bell curve is a little to the right of the male bell curve. For spatial abilities, it is the other way around. Does this mean men cannot be excellent writers, and women cannot be excellent mechanical engineers?

No.

It just means that if all else were equal, we would expect writing and mechanical engineering to have gender distributions that don't match the general population.