>>55245960In the context of Pokémon, I would argue that an Ace is relative to the goal of the team. In general, the Ace is the Pokémon the team is founded on. In great Pokémon battles, the player usually gets false confidence because the “easy” Pokémon are actually part of a setup strategy for the Ace to turn the tables and sweep.
Functionally, the ace can also be used to demonstrate something to the player (e.g. see most of the Paldea gym battles) or invoke emotions like Red sending out Pikachu first in the game right after Pokémon Yellow, Special Pikachu Edition.
In the case of Geeta’s first battle, most players won’t really be aware of her last Pokémon and the plot thickens when you suddenly see tons of them in Area Zero. Naturally, she swaps the order in her post DLC fight because she is now not serving the story, so true battle strategy is key.