Just FYI, you responded to a thread that's over 7 years old, so you probably won't get an immediate response from anyone in that thread, if you get a response from them at all.
In response to your questions, though, you can link as many separate files into yours as you want, regardless of discipline. If you've got the Revit Architecture/MEP/Structural version, then you should be able to copy/monitor anything from any other disciplines' file.
I'm not sure I understand your question about the 2 architectural files. Are you talking about something like a core/shell file and an interior finishes file? If so, then yes, you can link both into your project.