Again: a deck of cards does not give you a "perfect spread" or "average results", unless you very specifically pull every card in the deck once in a game. If you don't, you can pull two dodges in a row, reshuffle, and then pull two dodges in a row again. Sure, there's a fat chance of that. But there's also a fat chance of that happening on dice, so what's the difference? Other than the fact that you're shoehorning in a mechanic that wasn't meant to be in the game, that is.
My understanding is that this is pretty much exactly what they would do.
How would you propose to do that? Arbitrarily end the game once an attack or defence deck runs out? Stop attacking and defending once a deck runs out?