For sure. That would be the problem of everyone doing their own map without much collaboration. The story and gameplay could be disjointed, as well as the gameplay. That's probably why Karmakeld was initially wondering how multiple people could realistically work on the same campaignLooks like a new MoS.-like team is forming! You go guys! With all the talent you have combined, it will have great potential!
I do recommend that you all work on all maps though so that you all have the story written in the same "mood" and "feeling". Also, so that the overall gameplay goes together in a good manner!
The story would need to be hashed out really well at the beginning of the project, followed by a break up of the story by map to get the map sizes in a good place.
It might be fun to do a good vs. evil, but explore the evil side of things