I don't see any argument there at all. He just states that "centuries later" TP happens, and then goes on to explain some more theories that are based on this connection, most of which are invalid or incorrect. Are you referring to the hero's shade and/or Malon, both of which he even stated to be merely speculation?
When he introduces the concept of the hero's shade tying back to OoT/MM, he starts by stating that the hero's shade says he defeated Ganondorf, which is completely false. Next, he explains that MM-Link "must have" gotten lost and died in the woods. The words "must have" here highlight that he's using circular logic - a theory based on a theory in order to prove the original theory. He hasn't done anything to show that the hero's shade is MM-Link, but assumes it anyway in order to make a case for supporting it. You just can't do that. Can I say that I can yell at him because he must be within earshot? Surely, if I can yell at him, then he is within earshot. Since he's in earshot, the I can yell at him.
Finally, I don't know why he even bothered trying to compare the hero's shade's equipment with that of MM-Link. They're completely different, and calling it speculation doesn't change that. Speculating that an apple is the same as an orange is pointless and futile. I'd rather not get into his Malon argument at this time. It's pretty much the same circular logic. I think you've heard enough.