You forgot that Lyn is an Ace to start with. Now, why 50% Zygarde is a Novice is something I don't quite get; in its 50% form, Zygarde has the same Base Stat Total as the pseudo-legendaries (Dragonite, Tyranitar, Metagross, Salamence, Garchomp, Hydreigon, etc.), Mythical Pokémon (Mew, Celebi, Jirachi, Shaymin, Manaphy, Darkrai, Victini, etc.), and miscellaneous legendaries (Latias, Latios, Cresselia, etc.). Note that all of the Pokémon I listed are Spirits in Ultimate, and none of them are Novice rank. The pseudo-legends are all Advanced, and most Legendary or Mythical Pokémon are Ace or Legend ranks. Complete Zygarde being a Legend rank makes complete sense, since its Base Stat Total is on par with Arceus, and it’s kinda neat that Complete Zygarde is the only Legend rank Enhanced Spirit whose initial stage is a Novice. But seriously, 10% Zygarde would be a much better fit for Novice Rank, considering that its Base Stat Total is below 500.