yep, the nationality team structure is looks great, 20 Team Members from 8 countries. 
a diversified team structure (if they can work in harmony, which i m sure in this case) will be advantage in the other stages, every member can bring the best person needed from their country, 8 country means 8 options in finding best person to fit in to project.
diversification in genereal is an important key value
on the other hand, it could be hard to communicate very well if everybody is not zentralised somewhere. i assume they are parted in those countries they live in or are they focused somewhere?
I definitely think they know each other. I do not think anyone would want to go on a long journey with an unknown person.
More than likely, they met at a congress or worked together or at least some of them know each other personally.
They certainly had a fairly long time in which they put their ideas together to let go of such a big project.
This project has a very long journey and i hope it will really make a new history.
The Ehealth Members and Advisors I've been to so far have really shown a lot of knowledge about what they sell, Ehealth has come up in my concept, and it has certainly been collecting more admirers and potential investors every day, for this reason