Isn't all this complicated even more knowing that the shattering war happened 5000 years before the events of the game? Like the world was in the state we find it in when we start the game for 5k years before us...
How does this complicate anything? For 5k or so years the world was in a cosntant state of war between demigods and their followers, whith everyone endlessly respawning and being unable to die. It's honestly the only way to make the setting have any kind of sense. All the buildings that are left are basically castles/military bases/capital cities and everything else is in ruins. With most people slowly being driven mad because they can't die.
5000 years is...a long time. A lot of stuff happens in the meantime which can and does have repercussions when it comes to understanding the lore. Overlapping battles, victories, defeats, army concentrations, equipment used, battles between demigods, artillery used, date and time of building, strategic defenses and structural collapses archaeologically speaking creates a ton of issues when trying to clarify what the hell happened, in what order, by who, to whom, considering that either a bunch of rubble fell over other debris (important or not) or terrain alterations over time (or suddenly considering the universe an the setting) cover or change up the face of the world, thus hiding or destroying clues or evidence of various events that will no longer be known. All of this muddies the waters tremendously in an already vague enough world.