Your repeated use of the word "copies" suggests to me that you didn't read the article (specifically, the article's very first section which disposes of the strawman about "copying"). This article is part of a series I did on the Christ myth theory (links below). All I can do is make the case as well as I can. So I hardly just "assume" that Christianity isn't true. I've written dozens and dozens of articles that are critical of Christianity. Just because you don't read them, or just because you pretend to read one but really don't, doesn't mean those articles aren't there.
The reason Christianity is especially vulnerable to this kind of criticism, of course, is that Christianity is uniquely reliant on its narrative's so-called historicity. Other religions embrace their narrative's mythic status, whereas most Christians say the foundational events of their religion happened literally in history (especially Jesus's death and resurrection).
