Fair enough. But then again, even without the epilogue, much of what happens in it
as been heavily foreshadowed beforehand:
[LN V1 epilogue](/s "The legion cannon, how dysfunctional just about every aspect of the republic military was and how the legion were actually amassing forces, plus the other parts of Shin's prediction.
As for the survival of Shin's group... Well, their biggest problem was his brother. Once they got past the frontlines, avoiding patrols would've been easy. As for them running into another nation... It's a bit convenient, but not THAT far-fetched. I mean, even a dysfunctional mess like the Republic of Magnolia managed to survive so far.
As for it bringing her pain... well duh, they are fighting a losing battle and she is one of the very few military officers who takes her job seriously. ")