As far as I remember this suggestion (or a similar one) has already been made for Doom3.
Suggestion:
All the work of modders could be collected at a centralized station.
The work would include some kind of standarized readme to make it easier to credit the work.
Everyone is allowed to take work out of this pool as long as credit is given for all of the used material.
Why also let people use the material that don’t contribute to the pool?
If someone hasn’t talent or time to create material but has the ability to combine several materials to a good / new game why restrict this person?
So the idea is that there aren’t fixed teams.