I've about seven modules arranged like so:
I try to make it my policy to restrict code to the module that actually uses it. Code that is shared by multiple projects (3+) is sent to common. However, there are a few classes that are only used by two projects. In my most recent example, both Account and Processing need some Image Processing done.
Is it a code smell two have the same classes found in two modules? Should I move duplicate code into common as soon as it it's used more than once?