outhouse
Atheistically
. The various acceptance of books became the choice of the most powerful clergy.
No. No powerful clergy made this decision. Or we would know his name and specifics in detail.
Marcion was one of the first we know about to put together a personal collection that was found popular by many people. Even if he was viewed as heretical for his half collection.
It was not until after 325 BC that talk was starting on what would become the canon.
Constantine may have discussed his 50 bibles shortly after the Nicean council or even during but that is unknown with certainty. But having many bishops who were forced to unify the religion, there is no reason why what would be read would not be talked about in the few months they debated.
But in all, Paul and the gospels won out due to popularity, not one mans decision or a group, the group that survived used the text that lasted.
It won the test of time.