I generally agree. Fake Gods, being difficult and time-consuming to beat, reward with a better return on loot. Sometimes, you will hit a dry spell, but most often, you'll win a card every couple of matches (about 1 in 6 or 1 in 7, thus the 15% cited previously). You're also being heavily rewarded in points and coins, especially for mastery wins, so cards aren't your only reward.