Many of them are transform cards or tokens
Casting multiple counters each round can be taxing on your mana, so be sure to make liberal use of Rewind, Unwind, Snap and Frantic Search to keep pumping out Drakes
However people will only submit if they think the card is good enough to get rated a 10 and if it isn't then really there isn't too much point in submitting due to the cost and risk of not getting a 10
Two mana to destroy an enchantment and get a few Saproling tokens at the same time is incredible
The ideal gameplan for the archetype is to have a high-damage dealing Pokmon like Articuno ex up front, then snipe at your opponent with a Greninja (or two if you're living the dream) that's waiting in the wings
The process goes back and forth between the artist, Creatures, and The Pokmon Company until its complete and ready for printing