Originally Posted by
Airget
I doubt it, the closest we'll get is when the Companies unite under one flag to deal with the terror, odds are we'll have something like "The Order of Eorzea" in the next update which is a grand company composed of all 3 GC that may offer gear stats that we might not normally be able to get from our own GC.
Sure I'm assuming but odds are the Grand Companies will unite under one flag(temporarily) since everything seems to be coming down to the city-states to work together to deal with the Empire threat.