Sabayon User Assignment UI

(These are just some scribbled design notes for a dialog in Sabayon. Excuse the handwriting.)

Need a way to associate users with a profile and vice versa
Use cases:
1. Create a new profile; want to say which users use that profile
2. Create a new user; want to say which profile that user should use
3. User changes roles; want to change which profile she uses
4. User quits job; remove the user
Most of the above use cases are operations on a specific user - they belong in the UI for managing users, rather than the UI for managing profiles - e.g. system-config-users
Lets just deal with the profile side of things for now - it'll be a slightly more clunky UI for most use cases, but it will do
Where to put the dialog? Select profile, click on "Users" button?
Hmm, that's getting a bit crowded. How about:
What should be in the dialog?
1. The name of the profile
2. The list of users using that profile
3. Some way to add more users to the list
Ticking a box for each user seems a little clunky ... any better ideas?

Its much of a muchness, really. I think I prefer the first one.
One thing to brear in mind with this UI is that its possible to assign a user to more than one profile. Best thing to do is probably just automatically disassociate the user from other profiles before associating with a profile.