In regards to the assignment itself, that’s great, and there’s obviously a use for it.
My concern is how it would look on the profile page. Would you be displayed as your highest role, would both (or all) roles be displayed? This could cause confusion in the profile groups. Same concern applies to the group member list. Would someone be listed in both roles?
To clarify, this is what I am imagining would happen should the change be implemented:
This creates confusion, and additionally, the more roles they have, I would imagine the more cramped it would be.