"Yeah, you can tell me the stats don't change, but Cautious hits 6-dice scores a lot more frequently than Reckless, period. I dare you to prove me wrong, that your die rolling algos don't change between the two CPU's."
They don't, the CPU playstyles do. Reckless has a more "Keep going though you've got enough to bank" cautious is more likely to only for 4 dice max unless he hits it lucky and gets 2 sets of three etc.