I don't see how Dawntrail is "disjointed". With the exception of Solution Nine, all of Tural is under one rule and all the regions appear to link directly together physically in one long line even better than ARR since 1/3 of the zones aren't separated off on an island only reached by boat.
The territory we appear to cover on the world map seems to only be about the size of Eorzea and considering that Tural is exactly like the Americas where geography is oriented north-to-south vertically, that means a wider range of biomes due to the latitude differences. I'd much prefer they do it this way anyway unless you REALLY want 4 different jungle zones.
Solution Nine being different isn't any different from Garlean forts inside of Eorzea, Allagan ruins anywhere but mainly in HW where an entire Allagan sci-fi laboratory appears in an otherwise dark fantasy setting, or 1920/30s art deco skyscrapers and jazz showing up in Shadowbringers. The Niners themselves invading Tuliyollal in the trailer parallels Garlemald invading Eorzea as well.
I think the point that the OP is making that I agree with, is that unlike SB and EW, there is MUCH more continuity between areas we're going to. Unlike SB we're not dividing the expansion up into 2 completely separate corners of the world with completely different cultural aesthetics and separate plot lines. It's much more focused than EW where we went to an underground park/lab, frozen and destroyed Garlemald half a world away, the jungles of Thavnair on the opposite end of the continent from Garlemald, the friggin moon, time traveling to yet another floating lab 12,000 years ago, and then the far edge of the universe. We had no knowledge at all of the last 2 zones before Endwalker started and with the exception of Ultima Thule and the moon, none of them have any visual cues linking each other at all and none of them have anything really to do with each other. Dawntrail is much more focused.