18 Trainers
18 trainer cards + 2 birds... it seems like a strange deck design, but it's surprisingly effective! With this set up, you're guaranteed to start with your bird of choice, and your first Pokeball is guaranteed to grant your second bird. And since they're both EX cards, you basically only have 2 points to give in any given battle, so there's generally no need for more Pokemon in the deck.
Articuno has the advantage of Misty supporting it, meaning 2-3 coin flips on your first turn can fully set up this monster and potentially allow it to insta-wipe the field, resulting in a turn-1 win or an early onslaught of high damage that also hits the bench.
Zapdos is slower due to a lack of energy-generating cards, but it has the advantage of potentially one-hit-KOing any Pokemon in the game if you get lucky, while scoring an average of 100 damage on Thundering Hurricane for solid average performance.
The lack of additional Pokemon cards means that these decks are very susceptible to Sabrina, and aren't super adaptable. But when they work, they work!
18 Trainers + Articuno exGo to Deck
18 Trainers + Zapdos exGo to Deck