Wow this is an old thread.
I'm not sure what Mr. Cad is talking about either.
You can create a Revit Template file that can handle all trades. That's not a problem. You just need to create view templates and Filters so you can control who things would be displayed on a sheet.
This still goes back to my main point. You need to know what you're producing the model for. If you're only project scope is Coordination, then you really don't care about how things are going to be tagged or printed on a sheet. If you're only doing design intent, you may not be as worried about how well coordinated it is. Sometimes MEP folks like drawing Conduit and Pipe spaced further apart than actually needed so it shows up correctly on paper.
These all go back to LOD (Level of Development. And this Level of Development should be the only LOD you care about. There's also Level of Detail (LOD), Level of Design (LOD) and a few others that people have spread around. All totally different things). If you're using your Revit model to produce shop drawings, your LOD needs to be much higher and the level or care taken to produce also needs to be much higher as you're trying to model it exactly how it going to be built. So it'll need to be fully coordinated. If you're only required to show design intent because the Contractor is responsible for making the design work, you're really only talking about how each system goes together and you really only need to coordinate large items to make sure that the design is feasible and should be able to fit within the space provided.
Typically the reason you don't put all disciplines together is file size and number of people. If you were doing a large project and had 5 people for Arch, 2 people for Structural, 2 for Mech, 2 for Plumb, 2 for Elect, 2 for FP, 2 for Technology..... you're going to end up with more people in the central model than you really want. (5 or less is ideal, 10 is about the max, 15 works, but you won't be very productive.) There's almost a balanced curve where the more people you have working in the model the less efficient you become, because you'll need to have strict controls on who's modeling what, and where. You really need to compartmentalize the project.
I've recently completed a 1.4mil Sqft project. Super large project team (almost 150 users) working about 90 models, in separate offices and firms.
So can you put all your eggs in one basket, sure. Should you? All depends on your workflow.