But he also called them the MoraNg Tong, so either there's a lorebreaking error, or he's making stuff up and getting the name wrong.
A different pronunciation of a name is not lore breaking error its a voice acting error. There is nothing to dispute the fact the Mong Tong are gone. Red Mountain devastated Morrowind and the Argonians used the opportunity to sack the province, how wouldu the Mong Tong survive?
I have a curious question, back in Morrowind was the Morag Tong ever spoken in voice acting? There are quite a few words in real life that aren't pronounced like they are spelled. Perhaps your assumption on how the word is supposed to be pronounced is wrong.
Ha, it's like the Land Dreugh in Oblivion - no two voice actors pronounced it the same.
Some might call it realism, people from different parts of a single country will easily pronounce a word differently even when there both native speakers of the same language.
I don't like the whole night lady thing.
The Mong Tong were founded by Mephala.
I think assassins should be assassins and kill for the money, not some ancient corpse.
Then you don't think the Morag Tong should be a guild because they were never about money. They did it for religious and judicial reasons. The beliefs differed but they were every bit as religious as the Dark Brotherhood. The Dark Brotherhood is very much a business far more then the Morag Tong.
The Dark Brotherhood is a religious business.