I'm not disagreeing, but Bethesda is on record saying it may consider rebooting the Elder Scrolls series and my suggestion would be a rather effective way to reboot the Elder Scrolls series.
Actually, that was a journalist's mistake. I asked on twitter after that came out a while back, they aren't doing a full on continutiy reboot, at least not anytime soon. Also that would just be a stupid thing to do.
Mantling is not the same as incarnation period. No matter how you want to slice or dice it.
Talos was dragonborn an individual gifted with the soul of a dragon by Akatosh. He mantled Lorkhan to become divine.
Wulfharth on the other hand was an incarnation of Lorkhan. A totally different principle which is clearly seen in the way his multiple lives played out. (Heck this guy was reassembled from ashes after red mountain.)
TES lore can be a trap if you do not watch it..
But they mixed later on, didn't they? Or something. They were part of a unit by the end, along with Zurin Arctus.
Could Arngeir/Esbern be the Arctus this time or is that pushing it?
I don't think each one needs to be the same as the last one, as long as we have all the major parts spread over three people. Hjalti was the Dragonborn last time around, but he was also the rebel, who is Ulfric this time around (and note he asks for the Dragonborn to kill him/Tullius. He is a smarter man than he lets on, I think) and later the Ruling King (whose position of authority, if not title, is neatly filled by Tullius).
All the parts are there, they're just mixing differently from last time. I would expect, whichever ending winds up coming out the temporal soup, that the victor of Ulfric or Tullius will display a startling tendency to be credited with the actions of the Dragonborn at times and to seem to be at multiple major events that happened at the same time.