Importing into your architecture tools should never be done into the "work" database. Too many unwanted items might be created - remember that the source files don't have IDs, and therefore create new objects, even though the human-readable name might be the same.

In addition to this, some source files (BPMN for example) might be imported in the "wrong" model type, and their content will be copied into a new model of the correct model type, so that the initially imported model can be deleted.

Lastly, once your imported models make it into the Work DB normalization activities have to be done, before the model can go through the regular, well-defined QA and approval process.