Best Setup for 60 Systems developed by 5 Teams

We have:
- An organization of 80 professionals,
- Developing and maintaining about 60 SW Systems - 20 of which are active, i.e. have regular planned 'Maintenance' and 'New Dev' releases ... 40 of which have < 3 Bugs/New dev per year.
- The 80 professionals belong to 1 of these 5 'Organizational Teams': Customer Support, Technical Support, Development, Test and Project Management Teams

The 'Organizational Teams' must have a cross-System view on *all* Systems (e.g. Developers are responsible for developing *all* Systems).
Typically, 1 given WI type (e.g. Defect) is assigned from 1 'Organizational Team' to another during the workflow (e.g. Customer Support Assigns Defect to Technical Support Team).

What we've come up with in RTC (where we can only have 1 Project Area) is:
1 WI Category per System, 1 'System_Team_Area' Team Area per System (associated to the corresponding WI Category), 2 Timelines per System (1 Maintenance, 1 Main Dev).
We also created 5 Roles that roughly correspond to the 'Organizational Teams' naming and through which we can restrict who-does-what (e.g. only Developers can Resolve a Defect etc).

This provides us per-System Plans (i.e. we have 120 'Current' Iterations/Plans).
Using queries on the work items, 'Organizational Teams' can track e.g. all Open Defects across all Systems.
However, we can not have 1 per-'Organizational Team' Overview Plan, since each Timeline is related to 1 'System' and not to 1 'Organizational Team'. So the cross-System view can only be achieved using queries (as there can be no Plan spanning multiple Timelines).

Question: How could we best 'represent' the 'Organizational Team' in RTC (different from 'System_Team_Area', different from 'Roles') in our case ?
Thinking of just using a 'Enumeration' with the 5 names, and add 1 'Team Assignment' field to work items, which could then be queried.
Any other 'better idea' ?

Thanks

... "How could we best 'represent' the 'Organizational Team' in RTC ...
Why not use team areas?

What is the use of having a iteration plan with 1, 2 or even 3 bugs?