I found that if you do two rows of three and one row of four, you can get ten cards on, representing ten stacks of cards
Like Pikachus evolved form, Raichu, Golduck doesnt seem to get much attention usually because in the anime, Psyduck stays in its basic form
If each change takes the form of either cutting or adding a card instead of replacing a card, and you simply play a lot and cut or add cards as they seem necessary, you could potentially naturally evolve toward an optimal deck size of some number greater than 60
Abilities are, as stated before, just a consolidation of Pok-Powers and Pok-Bodies nothing new there
If you or your opponent have a monster in the Graveyard , you can put it on the field under your control