This has been something that I have thought about for a long time, ever since the end of era 1. We know that there is extra Preservation put inside the people of the basin (maybe the whole world, maybe not). What if the excess Ruin lies within the southern Scadrians? Harmony knew that to be balanced he needed to dump it, it worked out well having Preservation within humans.....so why not having a population with excess Ruin?
Probably crazy.