The difference between a Cambion and a Tiefling is often debated, personally it would seem to me that the difference is that a Cambion is in some sense more heavily embraced by its infernal parentage... raised in the hells, and its powers nurtured until it achieves full fiendhood.
Something like that, I just think it is weird that this game is treating it like they are the default fiendish entity.
To be fair, Devils are for the most part former mortals anyway. I have suspicion that if we go back far enough even the big name devils and demons are former mortals.
