The software isn't written yet. There's still time to modify the data model etc.
I was looking at the use case as each project/area having vertical orientation and the accounting as having horizontal orientation (or visa-versa), but that hasn't been very practical.
Now I am seeing the orientation as being more tree-like, where a primary subsite contains project/area subsites, and the primary subsite also has an instance that can access the other instances that are within the same subsite and subsites mounted within it.
Any suggestions?