Is anyone else dying to get to Garlemald?

[YianKutku]

It was my understanding that Drest, the marooned Juggernaut pilot in Raincatcher Gully was actually a member of the XIVth

Oh, you're right. I mistook Drest's mission as one from the VIIth around the time of Cartenau, since he was already in Eastern La Noscea for some time when Shamani stumbled across him. But checking the dialogue, the mission where he was shot down was three years ago, so well after Cartenau.

As far as 1.0 went Castrum Oriens did not exist physically or was not even mentioned at all, so I'm liable to take it that the Wall preceded Castrum Oriens' construction (by all accounts Garlean engineering is very adaptable and can be quickly constructed and modified with little effort, being mechanized and all, so this does not seem surprising). But if the lorebook says differently, I'd take that as a retcon. The castrum on the Ala Mhigan side of the border also being called Castrum Oriens may just have been for consistency's sake, rather than having any lore reasoning.

The lorebook actually agrees with you, which was why I was skeptical of the lorebook at first. Silvertear stopped the Empire's advance, so the Garleans constructed Baelsar's Wall and huddled behind it. After that, then the Garleans constructed Castrum Oriens.

The map provided in that section has the symbol for Castrum Oriens a small but noticeable distance from the symbol representing Baelsar's Wall, though. There are also arrows connecting all the castrums, mostly emanating from Castrum Centri to the others except Castrum Oriens, and having an arrow go from Ala Mhigo to Castrum Centri. It would make sense for these to be supply lines.

The arrow pointing to Castrum Oriens comes from Baelsar's Wall, right next to it. The implication is that Castrum Oriens, clearly in Shroud territory, is supplied by Baelsar's Wall.

Which is not exactly wrong, but in the Baelsar's Wall dungeon, we see a full Garlean stronghold, worthy of being called a castrum, built around that wall, and people refer to it as Castrum Oriens. And since there is also a Castrum Oriens on the Gyr Abania side of Baelsar's Wall, it would mean either Castrum Oriens is right next to Baelsar's Wall on the Ala Mhigan side (and so not quite in "Eorzean territory" as the passage from the lorebook states), or Castrum Oriens is built around Baelsar's Wall, incorporating it into its design. Which would in fact fit with both the lorebook and what we see, but again, I find it difficult to believe that Gaius waited until after the Battle of Cartenau to begin fortifying the Wall.