Ah, okay. He could be a rival, but the overall priority would be a unified collaborative effort. Since there are dozens of nations with citizens on the expedition, they probably wouldn't take kindly to a rivalry so apparent that it could interfere with progress. There's also the fact that, most likely, your doctor and Gharlan would fill different roles within the expedition, so their rivalry would probably be more of an intellectual one. Perhaps they play something like chess on their off time, always trying to better the other in games of strategy. 

And I say different roles because, if your character is a healer, his work probably wouldn't overlap with Gharlan's very much. Gharlan is the lead scientist on the expedition, and if you notice the pics I uploaded in the second post, I actually gave him a Sharlayan-like outfit, hehe. He's an Aetheryte expert and spent quite a lot of time analyzing the crystals brought back from the first expedition, which helped him fine-tune his crystal-lens goggles. 

Though I am curious what you meant by major patriotism? Were you thinking your character would be loyal to Old Sharlayan over the Fellowship, or that some of the characters would be more loyal to the Fellowship itself over individual countries? I'm sure there will be room for many variables of that nature, since one of the early plot threads will likely deal with mutineers.