I don’t know if you really meant it when you asked the question but the scenario for Final Cut Pro(FCP) would be pretty similar to the scenario you suggested for Avid. I would get three sets of drives, and have everything originate from the AE. In FCP I know I can have multiple projects open so I can simply drag clips from one project to another. In FCP the media file has the same name as the clip (unless you change it manually) So relinking media is easy to do. The only Avid Experience I have is limited to some logging and pulling select reels with a version of Media composer which I believe is at least ten years old. In that version it seems like I can only have one project at a time open (I could be wrong here) and that the media file is a numerical file name. So adding a new clip to another persons copy of the project and linking it to a media file that has been digitized by some one else seems like a potentially convoluted process (in my reptilian FCP brain).