That's right. Pairs (hardways) would come up slightly less often with these card-dice than with real dice.

Using 72 cards (12 of each number, 1 thru 6) the odds of any first card number is 12 in 72 (or 1 in 6 = 0.166667%). Let's say that card was a 4.

Now, the odds of a second 4 from the deck is now 11 in 71 = 0.15493%.

It would seem that hardways just became even harder to make (even though they're a pretty bad bet anyway). Since 2 of the instant craps numbers are pairs (1&1=2craps; 6&6=12craps), then also seems that it would be slightly harder to throw an instant loser, assuming you're a pass line bettor.

I haven't really analyzed this way to play, so there may be offsetting percentages that even it out.

Another way of setting up the deck of dice-cards would be to print a different PAIR of dice on each card (1-1, 1-2, 1-3, 1-4...up to 6-6). There are 36 possible outcomes (6x6). Then draw just 1 card per "throw".