You installed the wrong plugin to your artifactory. The first link http://docs.oracle.com/middleware/1212/wls/DEPGD/maven_deployer.htm#DEPGD383 in your question contains a note:
This plug-in is deprecated in version 12.1.2 of WebLogic Server. Oracle recommends that you instead use the WLS 12.1.2 Maven plug-in
This old plugin is only used for deployment. That's why you only see start/stop/deployment related goals. You should follow the installation instruction on the second link you provided http://docs.oracle.com/middleware/1212/wls/WLPRG/maven.htm#CHEGICCC. The new plugin includes goals for development purpose such as ws-clientgen