I don't know, Omnirizon...the more this issue is mulled over, the less it seems intentional (on whatever level), and the more it seems coincidental. And pertaining to Abyssia: Looking like a duck and walking like a duck ceases to apply when said duck is on fire
Molecular/cellular diversions are just as valid differences-if not more so-than cosmetic ones. And the fact that Niefelheim falls under the same categorical shift as Abyssia rules them out as human, or humanoid. If I met somebody tomorrow that was 24 feet tall, and surrounded by a personal blizzard, my first thought wouldn't be "what a fine example of humanity". At the very least, as much would separate such a being from a "purely, merely" human being as a sentient, intelligent, pacifistic monkey of the Buddhist faith.