Did you already read Andreis fabulous blog post about the matter?
Especially this one was a real enlightenment for me personally:
Everdo areas should not to be confused with areas of responsibility described in Getting Things Done as one of the horizons of focus.
The list of areas of responsibility is a tool to track and evaluate all the commitments that you have. On the other hand, Everdo Areas are intended for applying top-level filtering to your projects and actions to reduce clutter and simplify the choice of next actions.
In general, it’s not optimal to create an Everdo area for each area of responsibility. Instead, you should use the principles outlined in the previous section and try to clearly partition your items by context, environment or a time block.
The Everdo areas are more like top level roles. Of course embedded in those roles I have lots of different AoFs and AoRs to fulfill.