I think... in the end, I would have tried to not stand against the threat alone.

The undead, after all, albeit loosely, are allied. While the cities try to stand alone. Yes, they are far, but as we have seen, there are ways to travel among at least some of them.

And, besides, even as a ruler, not trying to do everything alone. At least some of the cities would have fared much better if the rulers had not been so distant from and secretive with their subjects.