If you treat a View as a Model you can't get independence. The Model (if you have a model) is actually tightly integrated with the persistence layer. Struts2 is a strict front-end framework, it doesn't contain models other than View models. So, staying independent it integrates with other frameworks like Hibernate or JPA where the model is mapped to the persistence layer. All the mappings you perform in Struts2 is between a View and Controller.
The links: