Why is Midori the final Arcade boss, not Rook

Just a thought i had, wouldn’t it make more sense lore-wise for Rook to be the final boss in arcade rather than Midor? In the arcade story everyone goes to morningstar to compete in the tournament, and most arcade endings have them at morningstar with Rook, but if you randomly fight Rook before the end of arcade it’s like you were already at morningstar and then went back to fight Midori. Also given that Rook created the tournament it feels like it would make more sense for him to be the final boss, but i can understand why Midori was chosen as he’s a dragon and all.

I think the cannon is that Grave and Midori are the finalists and Grave beats his master, that’s probably why.