One view of the Enterprise Architecture is the Services View, where you can look at the whole enterprise from the Business capabilities, expressed as Services (or Capabilities – where conceptual and not yet implemented), through Logical Design Services, through Implemented Services, right down into the Physical implementation elements such as software infrastructure Services (like unix FTP components, Browsers, Middleware, etc.) and Hardware Services (Servers, Routers, Printers, etc.).
See example diagram below for a simple idea of these (using Archimate Notation):
I therefore believe that showing all the Services used in the Enterprise is possible at the right level of granularity. Services are more than just Web Services or the middle layer of this diagram “IS Application SOA implemented services”.