When it comes to the first century Jewish law, Paul was a Pharisee (lawyer) of the Mosaic Law. Your James was a fisherman from Galilee brother of John sons of Zebedee, whom Jesus called “Sons of Boanerges” Sons of Thunder.
Oops! Wrong James again. “My” James is not the bother of John, he is the brother of Jesus! After the Resurrection of Jesus, our Lord made a special visit to James after he appeared to the 12.
“He appeared to Cephas, then to the twelve. After that He appeared to more than five hundred brethren at one time, most of whom remain until now, but some have fallen asleep; then He appeared to James, then to all the apostles.” (1 Corinthians 15:5-7)
Make all you want out of the fact that Jesus appeared to Peter before the 12 apostles, and then latter on to James, but at least His appearance to James was a special one to one visit, as it also was for Cephas.
I’m not ready to concede that the role Peter played was greater that that of James. But, of course, I could be wrong. But if I am wrong it remains very clear that James, the brother of Jesus, at least played a very significant role in the Church, far greater than most, if not all, of his peers!
BTW >>>
Lest we get too far from the original question of this thread. Note that St Paul called St Peter “Cephas” several times. Is it safe to assume from this that St Paul knew exactly what was meant by this name Jesus gave to him? And further, don’t you think that if St Paul fully understood this, wouldn’t he show some sort of submissiveness to St Peter’s authority if the Rock of the Church is a matter of authority (contrary to what I have been claiming)? Then showing St Paul’s submissiveness or non-submissiveness to St Peter could bear some weight to the understating of what “Petros” may mean. Yes? No?
St Paul submissiveness to the Counsel of Jerusalem can only count as submissiveness to Peter if a particular interpretation is imputed to Act 15, so how about looking to other examples. When St Paul said, “Recognizing the grace that had been given to me, James and Cephas and John, who were reputed to be pillars, gave to me and Barnabas the right hand of fellowship, so that we might go to the Gentiles and they to the circumcised.” (Galatians 2:9). Why the phrase, “who were reputed to be”? Why not “who were” pillars? (The KJV says, “who seemed to be”). The word there is “dokountes”, which means, “ones-being-supposed”.
Of course, the point I’m making here would apply first to James before it would to Cephas or John, but I still think it is a point worth looking at. Why would James, Cephas, and John only have a supposed authority? There were men that came from James to Galatia that said you need to be circumcised and ordered to obey the Law of Moses. The counsel of Acts 15 corrected these men. But St Paul said that even if these men correctly spoke for the authority of St James (and Cephas, and John) that “If we [Paul and Barnabas], or an angel from heaven [James, Cephas, or John], should preach to you a gospel contrary to what we have preached to you, he is to be accursed! As we have said before, so I say again now, if any man is preaching to you a gospel contrary to what you received, he is to be accursed!” (Galatians 1:8-9). What I put in “]”'s is what I believe was implied there.
Conclusion: Petros, the foundation of the Church, could not be an outside infallible authority with regard to Faith (and morals). Nor could even St James, or even an angel from heaven (much less men from James) hold the authority to alter or change the Faith that was ‘once for all’ delivered to the saints! As it says in 1 John 2:27, “But the anointing which ye have received of him abideth in you, and ye need not that any man teach you: but as the same anointing teacheth you of all things, and is truth, and is no lie, and even as it hath taught you, ye shall abide in him.” The foundation of the Church is inside of you, not outside of you.