[quote=@BigPapaBelial]
Would you mind if I offered another idea?

And bring in an equivalent to Old Sharlayan? Something like another neutral party. I'll think of a name for them. I'm hugely enamored of the Old Sharlayan aesthetic right now.

What with it being a nation of scholars, students, researchers and inventors. Maybe a contemporary of Dr. Gharlan? A Sharlayan League Aether-tech researcher. Rival schools perhaps kinda deal. And the Sharlayan league has sent my character as a kind of foil or attache to take part in the expedition.

He'd of course bring the latest in Sharlayan League research and healing gear. wink wink

Well that's what I'm thinking anyway.
[/quote]

Yeah, that would work! Since there are dozens of kingdoms allied with the Fellowship, you could model one after Old Sharlayan. Each nation would be completely independent with their own leaders and government, but they would send an Ambassador to Archades to sit on the Fellowship High Council and agree to a basic set of principles, similar to the United Nations in our world. 

If you're thinking your character will be older and on par with Gharlan, you could make him the chief medical expert on the expedition. Once they land, he could set up a clinic in the Midgar Colony. Though, if you're also wanting your character to go off on adventures with the lower ranking members of the expedition, it might be a good idea to create two characters, perhaps a master and apprentice. The master could be older and wiser and run the clinic in the colony while the apprentice joins the adventurers to go hunt down possible sites for Aetheryte mines and combat monsters. 

Doctor Gharlan invented crystal-lens goggles that allow them to detect the auras of Raw Aetheryte from a distance, even while it's still underground, so that helps them determine where to start digging. I imagine the expedition would have multiple small teams to fan out and search for potential mining locations. As for the exact number of people on the expedition, since establishing a permanent colony and developing a successful mining venture are the priorities, there would likely be around six hundred people total spread out over several ships, with the Blue Falcon as the head of the fleet. 

There will obviously be the adventurers and combat experts, but also people to build the colony, set up farms and ranches, work in the mines once they are established, hunt and gather food and resources, etc. 

However, you mentioned a possible foil, so if your character is on a secret mission to sabotage the expedition, perhaps the Old Sharlayan government has plans to slowly dismantle the Fellowship from within. Perhaps they have a secret alliance with Ishgard or Dravania, or maybe they have just grown concerned over the amount of power and influence the Fellowship High Council has cultivated. Ultimately, it's your decision.