I may be off here as well, I never like statistic, but:

If you have a box full of blue chips and red chips, same number of both, red chip wins.
Would you care if you are drawing from a box with 10 chips total or 1000 chips total?

If there are less cards, then yes there may be some cards gone that helped you, but there may also be cards gone that DIDNT help you, which incrases your chance. So since the cards are unknown, it doesnt matter how many there are.