You went with the assumption that Madara has the Human Path because he has Rinnegan. I went with the assumption that a Rinnegan user can learn every jutsu in existence.
The Sage had the Rinnegan and invented ninjutsu. My assuption is over the top with the purpose of showing that assumptions are bad and shouldn't be made in threads like those.
My assumption isn't an assumption as Manga shows that Madara can use the Six Paths Techniques.
Your assumption in the bold is flawed. Rinnegan users
can learn any jutsu in existence,
obviously not Special Techniques like Susanoo. Rinnegan uses
can't use any jutsu in existence. Use=/=Learn
The Sage invented the concept of Ninjutsu, not every ninjutsu in the world.