I suspect that you are imposing a very narrow and specific reading on a statement that is intentionally meant to be less narrow and specific. Particularly in the early days, lots of people were trying to figure out what this new religion was, and lots of people who were dissatisfied with some aspects of religious forms already in place were merging some of the new ideas with what they liked with various practices. Leading individuals here and there astray is not necessarily winning in a broad sense, although it has greater impact in a fledgling movement with relatively few followers. And it is particularly troublesome to avoid such mixing before more accepted ideas and practices are more fully formed. Paul’s personal history and commitment would have been one matter, and what he was preaching might well be a separate issue (although the credibility of what his message would have been somewhat dependent on the degree to which he was seen as a devoted leader to the new cause).