Check out my post about this... I had two cases where each case has 8 sketch cards... 7 of the sketches in each case were the same artists. The odds of randomly creating two cases sharing 7 of 8 artists from a list of 131 is so small that its like hitting the lotto.
Originally Posted by Rian Fike
Mars Attacks is by a different company. A very different company.
And, honestly, what you are describing could still be evidence of random distribution. It's like the lottery, it could come up 1, 2, 3, 4, 5, 6 every single day.