Is this Use Case possible?

The KEY here is that each level can access only that which has been pushed to them.
Otherwise, busybody supervisors and meddling senior management will either get confused (highly likely) or cause problems (not unusual).
Enforcing the "chain of command" and "need to know" are very important concepts here.
Obviously only certain content must undergo review by the full chain - but nevertheless - certain content must undergo review by the full chain.

Workflow Use Case: "Package Alpha"

1. Content created by Authorized Writer, "Package Alpha", Saved, Edited, Managed.
   
2. When content "Package Alpha" is complete, Pushed to Designated Reviewer by Authorized Writer using Workflow.
   
   [begin:Reviewer]
   
3. Any Reviewer can now see "Package Alpha". List of current work items provided by Views. Optionally Designated Reviewer notified via Triggers.
   
4. Designated Reviewer edits/approves/pushes "Package Alpha" to Designated Editor.
   
   [end/begin:Supervisor]

That sums it up nicely I hope. You may Fire when Ready, Gridley!

Thanks In Advance!