Can I setup Struts to use multiple configuration files ?

Yes ! Struts can use multiple configuration files.

Configuration example 

<servlet>

    <servlet-name>actionServlet</servlet-name>

    <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>

    <init-param>

        <param-name>config</param-name>

        <param-value>/WEB-INF/struts-config.xml,

                     /WEB-INF/struts-authentication.xml,

                     /WEB-INF/struts-help.xml

        </param-value>

    </init-param>

    <load-on-startup>1</load-on-startup>

</servlet>