Even with the taint removed, your problem is that the master is in RzaGroup-2, however the scheduler sorts the names and picks the one with the "smallest" name, in this case RzaGroup-1. The reason is that the operator will always do the same thing regardless of the ordering of the zones in the configuration. So we are working as designed.
We have no visibility of the number of tagged nodes. In fact in most deployments we wouldn't be given access to this information as we can then see the entire cluster, what it's labeled as, what docker images are installed on it... This is far to big a security risk to let us have access in the common case.