POP Authorisation using Groups

When POP Authorisation is set up using groups, when you have more than one group set up, it is the last person to authorise the PO whose name appears in the PO List as the Authoriser. Our client is querying this as he believes that Auditors will query it. For example, A1 can authorise £1000, A2 can authorise £5000, A3 can authorise £10000. A PO has been raised for £8500 and has been authorised by A2, A3 and A1. It is A1 who is showing as the authoriser. An Auditor would query why this user has authorised the order and they are below the limit. There needs to be an improvement in Sage to show all authorisers, or a report which will detail all authorisers for a PO.