
Thought I'd clarify a few things, just for the sake of doing so. I actually see the questions pop up quite a bit, and I figure clarification never hurts, even if it runs a tiny bit off tangent. Naturally, there are major spoilers below.
All of that aside, during the time skip, the Grand Companies worked together to rebuild Eorzea. They were quite active, both in defending the realm against the Garlean threat, as well as the plethora of monsters that now roamed unchecked across Eorzea. They were instrumental (alongside a rebirth of the adventuring trade) in defending laborers who sought to rebuild after the calamity.
All of that aside, during the time skip, the Grand Companies worked together to rebuild Eorzea. They were quite active, both in defending the realm against the Garlean threat, as well as the plethora of monsters that now roamed unchecked across Eorzea. They were instrumental (alongside a rebirth of the adventuring trade) in defending laborers who sought to rebuild after the calamity.