You made the assertion that they were spin-offs and not actual games.
They are actual games.
If you find a statement from Nintendo that says "these are not Zelda games", then I'll admit defeat(well, at least for this point)
I think it's absolutely ridiculous to say that certain games don't fit in on a timeline simply because they don't make sense.
That's why I personally believe there is no great timeline, and this is backed up when you have to remove several games from it just for it to make sense.