Maybe Nords just don't die? Maybe the dragons have nothing to do with them walking around. Even Serana said she would fool them as a little girl, and that was at least 2nd era. Dragons came back in the 4th, meaning they have been walking around since then despite dragons.
Edit: Nords who die in their sleep are still trying to get to Sovngarde. Or maybe some who died in battle were barred from Sovngarde, and are trying to get in. I know I wouldn't rest if that was me.
Maybe Nords just don't die? Maybe the dragons have nothing to do with them walking around. Even Serana said she would fool them as a little girl, and that was at least 2nd era. Dragons came back in the 4th, meaning they have been walking around since then despite dragons.
Edit: Nords who die in their sleep are still trying to get to Sovngarde. Or maybe some who died in battle were barred from Sovngarde, and are trying to get in. I know I wouldn't rest if that was me.