I recently stumbled onto something that might be a plothole (provided I did not forget or misunderstand something which might be the case).

As we know since 5.0 there are Unsundered and Sundered Ascians (and the Unnamed ones that were never actually explained).
Unsundered can continue to exist because their Soul does not disperse when their Body perishes, so they can possess other Bodies to continue living.

But as far as I know the Sundered cannot do that, so if the time of the Ancients was such a long time ago, how can any Sundered still exist after their natural lifespans ran out?
When a human dies, their Soul instantly exits their Body and disperses into Aether, which confirms their is no reincarnation so the last Sundered should have perished a long time ago without getting reborn.

Coming from this fact, it is an equally huge coincidence that 2 shards of the same Ancient would exist in the same time (WoL and Ardbert), but that as far as I have seen, there have been no Ascians with the same name at the same time (no 2 Loghrifs for example)

So, have I misunderstood anything, or have I discovered an unexplained plothole?^^