>>44192609>ZapdosOU
Assuming its stats are just normal Zapdos with its attack stats flipped, G-Zapdos will easily be the best one. Its STAB combo hits the vast majority of the game, all it needs is Brave Bird, Dual Wingbeat, or Drill Peck for Flying STAB and an Electric move for coverage. Bolt Beak would be really obnoxious on this thing even without STAB. I'm also hoping it gets Bulk Up, Roost, U-Turn, and Taunt so it can run set-up/stallbreaker sets.
It also benefits from Defiant a lot because it's physical attacker that doesn't care about Landorus-T at all. Defiant puts it at +1 against Intimidate and if Lando switches in on its signature move, it's basically +2 and Lando can't do much back to it now that Z-Fly and HP Ice are gone.
>MoltresBL/UU
Dark/Flying is another great STAB combo and it only needs a Fire move for coverage but it will probably be inferior to Hydreigon if it keeps normal Moltres's 90 speed. I think it will be more interesting if it gets a lot of utility moves like Foul Play, Will-o-wisp, Taunt, Defog, Roost, and Knock Off. Something like a bulky set that can spread burns and fish for Berserk boosts repeatedly with Roost.
>Articuno???
It's hard to tell with this one. It will probably be better than normal Articuno just by not being a defensive Ice/Flying type but it's not like Psychic/Flying is that much better. It only really needs Focus Blast or Aura Sphere for coverage but this thing is screwed if its stat spread is too similar to normal Articuno's. In any case, it will probably be the worst out of the Galarian trio.