No,
as I wrote before you need at least the SOAMANAGER and connect the consumer (SD, FI-AR) with the service provider (FSCM-CR) point to point (even it is the same system !). No need for extra systems,
About DNB: you could use the file from DNB and fill the data into FSCM with some BAPIs (FSBP...)
No need to use WS-RM for it then.
Hope this helps
Fritz