As I was reading all these posts I came up with my own hypothesis... I think the tech that Garlean got their hands on is tech from another age, like age of the ancients or what everyone refers to as gods now (kind of like in XIII) The Garleans heard there is more of this tech in Eorzea in Toto-Rak and the Darkhold, which explain's some of that old tech we find with the quest's inside of Toto-rak and such. I believe that "Dalamund" is like the penultimate weapon from that ancient generation, and Garlean had found out about it and Activated it and it is now moving to us. (Kind of like the Death Star Reference)