Well, let's take a close look at your statements. Here is what your church says.
From newadvent.org The belief in the corporeal assumption of Mary is founded on the apocryphal treatise De Obitu S. Dominae, bearing the name of St. John, which belongs however to the fourth or fifth century.
If we consult genuine writings in the East, it is mentioned in the sermons of St. Andrew of Crete (740AD)
And again from newadvent.org.
"In the West, St. Gregory of Tours (593 or 594) (De gloria mart., I, iv) mentions it first.
So your statement "Not one of the apostles, not one of the Apostolic Fathers or the next generation or the next or the next." is rather misleading isn't it. Why would we see any of those speak out against the belief if the belief didn't even surface until 100s of years later?
Now re-read the last four sentences of your post again. You're simply building on a false premise. Is that how you teach your parishioners? How gullible do you really think people are?
Well, considering the number of people who buy into that teaching.......