In Pokémon Origins, Red sees a image with the three legendary birds and Arcanine.
Why was Arcanine there? I mean, he's 'The Legendary Pokemon' but not a legendary Pokémon. In this question/answer, there is a comment by Rayz Rusher on the answer that Arcanine was originally a legendary Pokémon:
"...Nintendo first gave Zapdos, Articuno and Arcanine as the legendary trio. But they removed Arcanine as it would have been awkward. Two birds and a dog, huh!..."
This still does not add up because Pokémon Origins was created a while after they removed Arcanine. Any thoughts?