Services are a composition of resources.
They can be fine-grained or very complex.
Services can invoke services on remote servers in line and as part of the flow of that service.
There is no documented limit on the level of nesting of services across servers.
Given this service bus mashup ability, distributed applications are very simple to build.
Warewolf best practice is to build fine-grained services and compose more complex services from there in SOA fashion.