Please, Acts of the Apostles is useless fiction. There is no actual history of Peter and James associated with any church anywhere. There is no historical evidence anywhere that Peter and James lived anywhere and was associated with Judaism in any century. Saul/Paul was a fabricated converted in an attempt to historicise the fables of Jesus and the disciples.
While inventing witnesses would be nothing new, it's still not very clear why would anyone invent a non-witness who only saw the guy in visions after he died.
Plus, you still haven't presented a coherent story of how you imagine the whole thing worked, if you think they needed to invent the guy who founded this or that church. There had to have been A founder, because the church existed. Unless you want to claim that the gang in, say, Corinth, just miraculously sprung into existence by itself, SOMEONE had to be a first one there who convinced and baptized a few others, who then baptized more, and so on. At which point, if you want to put your words in someone's mouth, WTH, you can just put them in the mouth of that guy.
Visions are not and have never been accepted as historical accounts.
Yet you claim both that AND that they invented exactly that kind of witness and it was believed. Which of those is it, because you can't have both?
NT Paul, his letters and churches were fabricated no earlier than the 2nd century in an attempt to deceive believers he was a witness to the fables called the Gospels and Acts of the Apostles.
Yet you just said that such a testimony wouldn't have been accepted as a historical account. Which is it? Would people believe such a non-witness account to be historical or wouldn't they?
But more realistically, some would and some wouldn't, which brings us back to the issue of: why would anyone invent such a weak sauce link, if they had to invent a witness? The gospels and Acts already invented a couple dozen named people who would have been actual witnesses, in addition to multiple unnamed Pharisees, up to thousands of people present at this or that miracle, etc. They even have Jesus naming Peter his successor as church leader.
So exactly what is your story of what happened there, that they needed to invent a non-witness as a source, instead of using some of the already invented actual witnesses? Exactly what is the benefit of inventing a Paul guy who got a couple of things from Jesus in visions, instead of just forging a few more letters from Peter saying he actually got them from Jesus in person, while travelling with him for a year or three?
And I mean, the ONLY thing that Paul shares about Jesus ever actually saying or doing is the Lord's Supper. That's ALL the 'confirmation' that Paul provides for ANYTHING in the gospels. And his testimony is either from a vision or hearsay, since he wasn't there. But Peter and the other apostles were supposed to have actually been right there and actual first hand witnesses. If you need to write hundreds of pages in someone else's name just to invent someone to corroborate the Lord's Supper, why invent someone who ISN'T a witness?
Why not just forge one page from Peter or John, saying, "oh yeah, I was there. He said that."? I mean, WTH, not only both are supposed to be witnesses, as in actually mentioned by name as being there in the gospel, but the former is the supposed appointed spiritual successor and the latter was supposed to be the naked guy that Jesus was loving the crap out of at that party. Either one is both far more convincing and costs a lot less.