The IAAR list is used for IAAR membership marketing purposes and does not represent all ANAB registrars. Using the scheme as represented by the list PJR represents themselves to be the largest registrar however my current registrar has three time the certs as represented by the list... Getting back to the original issue, as long as a client wants to contract out their internal audits to their accredited registrar and the registrar uses a separate auditor group to perform the service then auditor impartiality could be maintained. Many small companies contract their audits out these days and the competent regristrars maintain separate audit groups to support he activity.