>>34897279They're not out of order.
Victini was deliberately given #000 in the Unova PokeDex (also making it appear before Snivy) to hide its existence. If Victini were assigned a number above 0, more people would try to find it to complete the dex and put it at harm. It's sort of a prize that only one person can have a PokeDex that has #000. As such, Victini is listed before other Gen V Pokemon.
Landorus is listed after Reshiram and Zekrom because you can't get it in BW until the post-game. The other 2 Kami Pokemon can be obtained before you beat the story.
Magearna is post-game. Marshadow is post-game. Poipole and the other Gen 7 Pokemon that debut in USUM are deliberately ordered according to their encounters. Naturally Poipole appears first, since you can get it before the post-game. (Stakataka and Blacephalon are post-game. Zeraora is Mythical.)
