You are very confused - like the scripture with the Sadducees yesterday.  God calls men and women to priesthood which is why they are both physically and spiritually capable of performing all the tasks of a priest, bishop, cardinal or Pope.  

God calls both men and women to parenthood which is why there is no imbalance in this vocation either.  Women are not more important parents than Fathers.  

Just because men are capable of being fathers, and Jesus was never a father, does not result in fertile men can't become priests.  Having one capability does not negate having other capabilities.  

Whenever we keep people from what God has called them to become based on how they are born, and are capable of performing, we harm them greatly.  We imprison them though they did no crime.  We diminish their humanity.  This results in the person feeling hated and betrayed by their own people, and it weakens their faith, in Christ, who has promised justice to all of his followers.