Tales from the Dawn #3: "A Question of Life" (Hermes)

[Brinne]

I am suspect about the description given in NieR, not because Emet is inherently untrustworthy in describing past events but because it contradicts things he says in the game.

When he describes and demonstrates the idea of sundering to us, it's simply splitting a being into identical copies with weakened attributes. If sundering truly reduced its victims to primitive incoherence, why not say so there? Why not drive home the full horror of what he witnessed his people reduced to?

Well, we know they couldn't actually have been simply made into identical copies, because it's since been confirmed - not just in NieR - that the Sundered races are the reincarnated copies of the Ancients, but aren't identical to them and had to evolve into their current forms. And from the beginning, all Sundered are tiny, size-wise, compared to the Ancients, to reflect their 'reduced' state. You can chalk it up to a partial retcon or Emet-Selch simplifying the explanation for whatever reason - for expedience or to make sure we understood the basic concept, or both - speculate however you want - but even given what we knew back in Shadowbringers, if he was actually showing the true effects of the Sundering, the Ryne copies he made as an example should have been half the height of the original Ryne, at the very least.