My point is it is very unlikely that there will ever be a High Rock and Skyrim Alliance. Especially without Imperial governance. They'll just fall in to regional feuds with no central government.
What is the basis of this argument? I'm pretty sure the Bretons don't want to be wiped out by Thalmor. Skyrim promising not to attempt to rule them like the empire did would be a decent incentive for them. Doubly so if they've already secured a hammerfell alliance to support their southern border.
The Ghost only mentions the name Hjalti, from what I remember. Unless I'm missing something? What side was that Ghost fighting for in that battlefield? He says something about Hjalti making a promise or some kind of battle bond.. but I can't tell if they were fighting on the side of the Nords or with the "Tiber Septim" mentioned in the book on Sancre Tor. Or if Hjalti is the Tiber Septim of Sancre Tor.
The fact that he calls YOU, the PC, Hjalti is even more strange.. but whatever. Beside the point.
Hjalti is from Arcturian Heresy. Stated as Tiber's real name Hjalti Early-Beard isn't very Bretonish(Though he is rumored to have been born in high rock). He mistakes you for Hjalti because when nords looked upon him after his visit with the greybeards, they saw only a dragon. He saw the same with you.