Look, just to make it clear, I don't claim to be sure that some guy called Paul actually started a bunch of churches. I don't know that.
There is a historical necessity that SOMEONE must have started those gentile churches, but frankly, nothing hinges on him being actually named Paul. He could have been called Jerry for all I care. Or a composite figure of the apostles Curly, Larry and Moe. I'll keep calling that SOMEONE Paul, for clarity sake, but otherwise it's as open as it gets.
So, you don't care if the Epistles were falsely attributed to Paul. It would not matter to you if the Epistles were really written in the 2nd century by multiple persons like Larry, Jerry, Harry, Moe and Curly.
You will keeping calling the person Paul.
You don't know and you don't care.
Well, the people who started the Christian cults were not named Paul and did not use the Pauline Epistles.
Examine Justin's "First Apology"
... There was a Samaritan, Simon, a native of the village called Gitto, who in the reign of Claudius Caesar, and in your royal city of Rome, did mighty acts of magic, by virtue of the art of the devils operating in him.
He was considered a god, and as a god was honoured by you ........ And almost all the Samaritans, and a few even of other nations, worship him, and acknowledge him as the first god..... And a man, Meander, also a Samaritan, of the town Capparetaea, a disciple of Simon...... He persuaded those who adhered to him that they should never die, and even now there are some living who hold this opinion of his.
And there is Marcion, a man of Pontus, who is even at this day alive, and teaching his disciples to believe in some other god greater than the Creator.......... All who take their opinions from these men, are, as we before said, called Christians...
Justin's Dialogue With Trypho
And, 'Many false Christs and false apostles shall arise, and shall deceive many of the faithful................. Some are called Marcians, and some Valentinians, and some Basilidians, and some Saturnilians, and others by other name..
Simon Magus, Meander, Marcus, Valentinus, Basilides, Saturnilus, Ptolemy, Colorbasus, Carpocrates, Marcion and others started Christian cults before the one you call Paul and the Epistles were fabricated.
See Against Heresies attributed to Irenaeus.
See "Refutation of All Heresies" attributed to Hippolytus.
http://www.earlychristianwritings.com/text/irenaeus-book1.html
https://www.newadvent.org/fathers/050110.htm
The start of Christian cults had nothing whatsoever to do with NT Jesus, the disciples and the one you call Paul.