As for your comments that Outside arguments are a no-no, I wouldn't say that's entirely true. It's just a different kind of argument, and it answers different questions. If you wish to view the Zelda universe as a consistent, self-contained system (as we seem to be doing here), then of course Outside arguments will be useless, and perhaps even akin to "giving up." However, I don't think that it is always wise to ignore Outside arguments. The Zelda universe is, after all, a human creation. It's possible, even probable, that the creators were not trying to fit every single detail together, and/or simply were negligent. There is no way to prove this, but it's a possibility, and an important one. 

What I'm trying to say is, if you only restrict yourself to Inside arguments, you will drive yourself crazy. There are probably certain things that the creators didn't anticipate, and weren't being careful about. To use Inside arguments to try to unite all these elements could lead you away from more useful studies. That's all. I'm not suggesting that we use Outside arguments to settle debates; rather, we should remember these kinds of arguments to give us caution. We don't want to waste our time going too far into topics that may not have been intended to be consistent.