This is working with the Maven "org.wildfly.arquillian" group artifacts instead, having versions matching the Wildfly J2EE spec instead of the Wildfly container version, seems more reasonable both by name and version numbering.
I feel there is no need to keep this open any longer.
Sorry for late reply.
yes we split arquillian containers out of main wildfly codebase after 8.x so they can have their own lifecycle of fixes and changes outside of WildFly releases.
Code is now at https://github.com/wildfly/wildfly-arquillian
and as you found out, groupid changed to org.wildfly.arquillian as result of this.