[Acts 15]You are correct. Peter did speak....so did Barnabas and Paul (verse 12)....but James was the one who was in charge (verse 19), and he was the flesh and blood son of Mary and Joseph....and the flesh and blood half brother of Our Lord.
We have Biblical proof that James was the leader of the Jerusalem Church as well as historical proof. Josephus mentions him by name and calls him the brother of Jesus [Antiquities XX, Chapter IX, Paragraph I.
Even though James may have been the leader of the Jerusalem church, I posted many istances where Peter ranked ahead of Peter. Peter was the first Pope.
Do you want me to post the list of Popes?