Well, NXE 3-8 itself, where the explanation for this is first given AFAIK, asks the question "How do -you- explain that both Achilles and Gilgamesh predate Christ?" - and Gendou responds "How do you know they do?".
Meshing that with a setting where inaccuracy of the historical record isn't as plausible wouldn't be entirely trivial, but should be doable, without some of the hoop-jumping you're looking at.
Also, I understand the Heroic Spirits as more or less deriving their existence from their legends, even if they didn't actually exist the way the legend depicts them. Add in the idea that not every incarnation of the Eternal Soldier necessarily knows that that's who and what he is, and it doesn't seem impossible that you could have the Eternal Solder born as Gilgamesh, who enters into legend (and develops into a Heroic Spirit) as something independent from the Eternal Soldier, who has a legend and is a Heroic Spirit of his own.
If I were working on something like this, I'd probably just say that although the Eternal Soldier's reincarnations are sequential from his own perspective, they aren't necessarily in order with respect to linear time - a variant of the seed idea for a religion I came up with a decade or two back, in which that same idea is applied to the only soul which exists, and everyone who's ever lived has been an incarnation of that soul.
Also, I agree: what is this doing in "should not be"?
Meshing that with a setting where inaccuracy of the historical record isn't as plausible wouldn't be entirely trivial, but should be doable, without some of the hoop-jumping you're looking at.
Also, I understand the Heroic Spirits as more or less deriving their existence from their legends, even if they didn't actually exist the way the legend depicts them. Add in the idea that not every incarnation of the Eternal Soldier necessarily knows that that's who and what he is, and it doesn't seem impossible that you could have the Eternal Solder born as Gilgamesh, who enters into legend (and develops into a Heroic Spirit) as something independent from the Eternal Soldier, who has a legend and is a Heroic Spirit of his own.
If I were working on something like this, I'd probably just say that although the Eternal Soldier's reincarnations are sequential from his own perspective, they aren't necessarily in order with respect to linear time - a variant of the seed idea for a religion I came up with a decade or two back, in which that same idea is applied to the only soul which exists, and everyone who's ever lived has been an incarnation of that soul.
Also, I agree: what is this doing in "should not be"?