No, it does not rely on the people to be merely mentioned, if you think that you have read the article (which is incredibly simplified by the way). The Isnad system is quite strong. Numerous independent studies have been done by non-Muslims: eg. Motzki
Hadith criticism is ridiculously strict. You are again speculation on a subject you know nothing about.
It's infinitely better then anonymous gospels that we assume the author got it right because the author didn't give us his detailed source for every single quote and statement (which is done by the hadith).
The Torah is the oldest literature on Abraham yet it comes from Moses according to tradition. The Torah today was redacted and edited during Babylonian exile.
I've also barely linked anything, I've only linked the Famous hadith works of Sunnis. I can go to the Shi'a (which always argue with Sunni theology) as well or also link more obscure books. And since interpretations of actions are allowed, not just reports, I can link the numerous Sharhs or tafsirs. Again I'm not bother because it isn't exactly the contest your trying to make it into.