Many parent groups vs node-references

Is it better to have many levels of parent groups or just node references?

Given the following scenario:

Vendors
|__ Products
|__ Clients
|__ Wish lists

It's easy to see that Vendor is the group, Products and Clients are that groups content, and Wish lists can be content of the Clients, which means that they would be "Group/Group Content"

Assuming that we want to create Malls as another parent of the vendors so they can be managed by Mall managers that sell space in the mall to the Vendors, do we create yet another content type, "Malls", and make that a Group, and change Vendors to "Group/Group Content"?