I have to say I really don't understand why the writers chose the route of "Venat deliberately caused the Sundering" when there were other neater and less questionable (and more consistent with past information) ways to have it happen. It could have been an accident or an unexpected result of sundering Zodiark or it really was cosmically necessary for some reason, and once it had happened, the suffering that would be wrought to repair the world would be worse than the effects of being sundered in the first place.
I feel like the writers may not have had enough of a clear idea of what happened when they set out the earlier parts of the plot, and now haven't been able to bring the answers together successfully. Either that or the original idea got changed and lost in a lot of workshopping and they failed to notice that it doesn't really work in the larger scheme of things.
