The design is perfect, that I do believe.
I actually believe that you were considering the design of humans as heterosexual, and the idea that it works well for you, and that you enjoy how it all works. You didn't mention being against homosexuality, but something tells me you are?
Anyway, the OP brought up an alternative approach for providing "man" with a companion, the original being Eve, who was "created" directly by the hand of God, for the purpose of being a companion for Adam. But when Eve ate of the fruit, suddenly God decided to make "chid birth" painful, to punish women forever. So, what God really needed was the perfect place for Adam to insert his penis, and allow viable offspring. Imagine that. No more rib magic required!
I don't know if you are a parent, but what lengths would you go to if you could take child birth pains from your spouse? I wanted to take them all away for my wife, and if I had god powers, I would. Would you? Or do you believe that all women, forever, should endure painful child birth because of Eve's actions?