I don't know about that, I think having more people working on a single project
is a reliable way of speeding up a project and completing it rather than one person working alone, especially on something as large as this.
Duplication is a good thing, yeah, but when you're talking about remaking a
whole province, which is larger, with more settlements, more NPCs and quests, and more diverse and most likely detailed models than the original game, if you do it right, it's just not reasonable to expect to make it all on your own. Just think of the humungous size
of a province mod, and it becomes obvious.
The idea of each person making a small area of Black Marsh is a good idea, and joining the existing argonia project is even better.
My advice, FlamingPlatypus, is to just mod whatever you want, it's a hobby not a job.
I'm just giving advice.