Please understand that I am not an authority on this one, having not done SOAP in quite some time now, but ...

The WSDL is (afaik...) an external description of what your service has to offer.   Your implementation must conform to it, but your server-side code is not influenced by it.   (It would be very nice if it did, and perhaps there is another package that does.)

As guide.soap.com indicates, access can either be dynamic or static.   “Dynamic” means that you specify a directory-name, and Perl looks for a module within that directory.   If it finds one, it loads it and uses it.   (See: "Different modules on one server.")   A hybrid approach can also be used.   But these implementation details are not apparent to the client.