Support for multiple authors has been designed in, but it hasn't been fully implemented. There are a lot of complexities that arise from having multiple people concurrently authoring content within the same campaign. What if UserA and UserB both make changes to the same content and then sync to the server? What if UserA should only have access to certain parts of the campaign and not to others, while UserB has access to a different subset and UserC has access to everything?
All of this is part of the plan (and built into the design), but it's going to take us some time to get it all implemented.
