I don't understando people keep throwing divinity 2 at the end of the chronology.
Zix Zax is less "advanced" in the divinity 2 and the dragon tower is actually the same as the void area (where the generals lived) in original sin but before being ripped apart and staying in another dimension... These things put it pretty early in the timeline
Divinity 2 is set in the year 1300, Original sin is at the beginning of that calendar; the others are set between about 1220-1250 as I recall.
The maps are quite speculative (speaking as one of the speculators) and Larian have never confirmed the relative locations except where explicitly named e.g. Aleroth, and nor do I expect they will; though I would hazard a guess that the "void area" is significantly to the south of Sentinel Island and the fjords.