Disable AAR on Admin Add User page

I have a mix of roles, about half of which are user-choice at registration (ex. "Member", "Guest"), and half of which are assigned by administrator only (ex. "Editor", "Administrator"). Not all overlap, eg. an "Editor" is neither a Member nor a Guest. However, I want to require a user-registration to select either Member or Guest.

The problem occurs when an Administrator is trying to add a new user who is an Editor. When an administrator creates a new user, AAR adds its own fieldset for roles just below the full administrator assign roles list. This forces the administrator to give the newly created editor either the Member or Guest role as well, just to get past the AAR validation.

Seems like there's no good reason for AAR to be enabled on the administer/add user page. Only gets in the way. Easiest just to take it out.