you can use “Local Service Development” feature in Designer to store packages in a version control system (repository) like SVN or Git.
You can built the template service in a dedicated package for templates and then ask your developers to copy these services to the package/folder where the new service should be located and then add the custom code.
I cannot see the benefit of having a script to copy the service template to a new service instead of just copying it in the Designer manually.
Additionally as there a several types of nodes which can be created (where some of them have additional options during creation) this gets somehow complicated.
What we want is to have an automatic process wherein once you run this Java (Jar File),
it will automatically copy the template/package on another outside IS or Repository,
then load in the local IS, and lastly, run in webMethods.