in the first example, $body and $header appear to be redundant. Also it doesn't seem that this method of RPC doesn't allow variables to be passed to the method

Well they're not redundant, they are the variables, encoded in different ways (raw xml, objects...), see

http://cpansearch.perl.org/src/MKUTTER/SOAP-WSDL-2.00.10/t/016_client_object.t

http://cpansearch.perl.org/src/MKUTTER/SOAP-WSDL-2.00.10/t/006_client.t

See also http://search.cpan.org/dist/SOAP-WSDL/lib/SOAP/WSDL/Manual.pod and use wsdl2perl

On the other hand, SOAP::Simple is simpler, see Re^11: Soap::Lite and Complex Types with WSDL

Obviously $address and $IP have been replaced with anonymous data in the sample.

FYI, http://example.com of http://localhost/ are the official anonymous $address