If you don't know the differences between them, or whether there are any at all, why then do you yourself claim that there are 41,000 different Protestant denominations?
And you're right - until you yourself can back up the claim that there are 41,000 theologically different Protestant denominations, then this is where your story ends.
http://en.wikipedia.org/wiki/List_of_Christian_denominations
See Note.
From the Internet, listed above:
Note: This is not a complete list, but aims to provide a comprehensible overview of the diversity among denominations of Christianity. As there are reported to be approximately 41,000 Christian denominations, many of which cannot be verified to be significant, only those denominations with Wikipedia articles will be listed in order to ensure that all entries on this list are notable and verifiable.
Granted, Wiki isn't the Gospel, but it's a source of information that MANY internet folks use.