If people recall, in the storyline for the Leviathan fight, in order to carry enough crystals to weaken Levithan, we needed a large boat. Bigger than Limsa had. So what did we do?

Take two boats and tie them together.

Why can't we take two servers and tie them together?

Make them both refer to the same database character storage is in. Maybe add a choice on picking your character similar to how the instanced zones work, allowing them to Balmung 1 or Balmung 2 or no preference?

One hurdle I can think of is public chats (Say, shout, yell) won't necessarily cross-over. I don't see how tells, linkshell, and FC chat would be an issue because of the instanced zones like we have now work with it.

Another is hunt mobs, theoretically one would spawn on each like they do on instanced zones. Maybe make like a 2-3 hour delay before you can switch to the other one? I'd think most groups would figure out a primary choice anyways.

I'm not sure how feasible this would be, I'm not a server admin. Just a random thought I had that's probably dumb.