That doesn't quite work, since Ganon in ALttP is clearly depicted as having the full Triforce, not just one part of it.
Yes, which is where the DT explanation comes into play.
In ALttP's manual, it didn't technically say that Ganon got the full Triforce at that point, even if we know sometime prior to ALttP that happened, due to him having the full TF in ALttP itself. As explained, Rauru says that Ganon got the Triforce, but we see that he only got the ToP at that point in time. Doesn't mean he doesn't get the rest later, though, which he does in the DT ending to OoT.
This is why the Downfall timeline exists; to fix this plothole between ALttP and OoT.
I agree with you on that, as said above.
Keep in mind much of this was going on the late 1990s. For quite some time, NoA was the only source of canon information for quite a few people because we didn't have access to the information from NoJ as readily.
Correct me if I'm wrong, but earlier, you made it sound like Nintendo had always intended for all Links to be the same and didn't retcon that until later, which is false. Even if you only had access to faulty info, that doesn't mean the other, truer info didn't exist, and you seemed to be unaware of this info existing.
This conversation makes me want to start a new topic that goes indepth on the developmental history of the timeline. It could clear up alot of misconceptions that people have about the nature of the timeline.