Model a Hierarchy Organizational Structure with SharePoint 2010

I'm about to model an organization with SharePoint 2010. I found out there are lots of Task Passing through different boxes.

First, I tried to create different subsites for each box. Then I create some custom workflow activities to create subsites dynamically and copy lists and list items between subsites. The problem is data load over this list item passing. Also, there is some reasons behind not supporting subsites negotiations by SharePoint definitely.

Now, I don't know how to implement an organizational hierarchy structure with sharepoint, as when user log in, he traverse over different boxes, view tasks and progresses, based on his roles, something like a page per box, or subsite per box, orI don't know what per box.

What do you suggest?

RO