Paul gets a lot of words in, is all, seemingly because he was a prolific writer. Some religions rely more on him for structure than others, but it's also evident that even in the first century there were differences in that way and that it was generally accepted that not all congregations of Christians were exactly the same.
They strove for a certain uniformity in belief in the main concepts of Christian belief, but differed on others that were less vital, from what I can see. Kind of like Christianity is now. The absolute conformity of belief the Witnesses pretend they have never existed and may not have even been intended by Christ or the apostles, from what I can see.
I say "pretend" because if you've just traveled around the country or gone to another country, Witnesses can be quite different in practice and appearance from place to place.