It turns out that MacDuff was IIRC "from his mother's womb untimely rip'd". IOW, he was a Cesarean section child so he wasn't truly born of woman.
This always seemed like stupid explination to me. (And one of the reasons I never liked
MacBeth. )
How is a child born by C-section not born of woman?
A C-section child is store born. No one would ever claim that they weren't actually born becuase they were a C-section baby.
And they had to be born of woman. They weren't cut out of a pumpkin.
Anyway, after recalling all this stuff, I suppose the significance is both the play MacDuff and Superman's robot are both not born of woman.
That's an interesting thought.
It certainly sounds better than anything I could come up with.
Mike