Gradle -> How to omit some jars from WEB-INF/lib

I have a subproject with a war spec that looks like this:

war {
    from('resources')  {
        include '*.properties'
        into 'WEB-INF/classes/'
    }    
    webXml = file('src/main/webapp/WEB-INF/web.xml')
}

Works great. Creates a single, fat war file that is deployable to Tomcat. Problem is, when deploying to TomEE and JBoss, I run into conflicts (ie with Javax Servlet, Jersey, etc). So I want to exclude a set of jars from being war'd. I looked at the Gradle war documentation, and it looks like I need to use excludes for this. I tried it two different ways, and the jars are not excluded from the war:

war {

    // copy properties file in classes so that 
    // they may be loaded from classpath
    from('resources')  {
        include '*.properties'
        into 'WEB-INF/classes/'
    }

    // specify web xml
    webXml = file('src/main/webapp/WEB-INF/web.xml')

    // remove jars that conflict with TomEE
    exclude '**/javax.inject-1.jar'
    exclude '**/javax.servlet-2.5.0.v201103041518.jar'
    exclude '**/servlet-api-2.5.jar'
    exclude '**/validation-api-1.0.0.GA.jar'

}

This is in a subproject (karyon-examples) within the NetFlix/karyon project hosted on github. The dependencies in the subproject look like this:

dependencies {
    compile 'org.slf4j:slf4j-api:1.7.0'
    runtime 'org.slf4j:slf4j-simple:1.7.0'
    compile project(':karyon-extensions')
    compile project(':karyon-admin-web')
}

And I want to avoid editing things like compile versus runtime dependencies, especially in other files and subprojects. In fact the jars I am trying to exclude above are benign when running with jetty and regular tomcat.

I simply want to exclude these jars without complicating the build scripts. What am I missing?

Thanks