[CentOS] Centos 7 Adding KDE as extra option

Folks

While trying to add a second desktop to my Centos7 installation (I 
had GNOME3, wanted to add KDE as an alternate), the install failed:

>yum groupinstall "KDE Plasma Workspaces"
<snip>
>--> Finished Dependency Resolution
>Error: Package: systemd-python-208-20.el7.x86_64 (base)
>            Requires: systemd = 208-20.el7
>            Installed: systemd-208-20.el7_1.5.x86_64 (@updates)
>                systemd = 208-20.el7_1.5
>            Available: systemd-208-20.el7.x86_64 (base)
>                systemd = 208-20.el7
>Error: Package: 32:bind-libs-9.9.4-18.el7.x86_64 (base)
>            Requires: bind-license = 32:9.9.4-18.el7
>            Installed: 32:bind-license-9.9.4-18.el7_1.1.noarch (@updates)
>                bind-license = 32:9.9.4-18.el7_1.1
>            Available: 32:bind-license-9.9.4-18.el7.noarch (base)
>                bind-license = 32:9.9.4-18.el7
>Error: Package: libreport-2.1.11-21.el7.centos.0.4.x86_64 (base)
>            Requires: libreport-filesystem = 2.1.11-21.el7.centos.0.4
>            Installed: 
> libreport-filesystem-2.1.11-23.el7.centos.0.1.x86_64 (@updates)
>                libreport-filesystem = 2.1.11-23.el7.centos.0.1
>            Available: 
> libreport-filesystem-2.1.11-21.el7.centos.0.4.x86_64 (base)
>                libreport-filesystem = 2.1.11-21.el7.centos.0.4
>Error: Package: 1:cups-client-1.6.3-17.el7.x86_64 (base)
>            Requires: cups-libs(x86-64) = 1:1.6.3-17.el7
>            Installed: 1:cups-libs-1.6.3-17.el7_1.1.x86_64 (@updates)
>                cups-libs(x86-64) = 1:1.6.3-17.el7_1.1
>            Available: 1:cups-libs-1.6.3-17.el7.x86_64 (base)
>                cups-libs(x86-64) = 1:1.6.3-17.el7
>Error: Package: 1:cups-1.6.3-17.el7.x86_64 (base)
>            Requires: cups-libs(x86-64) = 1:1.6.3-17.el7
>            Installed: 1:cups-libs-1.6.3-17.el7_1.1.x86_64 (@updates)
>                cups-libs(x86-64) = 1:1.6.3-17.el7_1.1
>            Available: 1:cups-libs-1.6.3-17.el7.x86_64 (base)
>                cups-libs(x86-64) = 1:1.6.3-17.el7
>  You could try using --skip-broken to work around the problem
>  You could try running: rpm -Va --nofiles --nodigest

Trying the --skip-broken option gave a large set of protected 
multilib version errors, so it didn't work either.
The following is the repo list:

>[root at xxxxx ~]# yum repolist
>Loaded plugins: fastestmirror, langpacks, priorities
>Loading mirror speeds from cached hostfile
>  * base: mirror.pac-12.org
>  * centosplus: mirrors.unifiedlayer.com
>  * epel: mirror.sfo12.us.leaseweb.net
>  * extras: mirror.pac-12.org
>  * updates: mirrors.xmission.com
>1452 packages excluded due to repository priority protections
>repo id                                   repo 
>name                                                             status
>base/7/x86_64                             CentOS-7 - 
>Base                                                          8,652
>centosplus/7/x86_64                       CentOS-7 - 
>Plus                                                          40+13
>cr/7/x86_64                               CentOS-7 - 
>cr                                                                0
>*epel/x86_64                              Extra Packages for 
>Enterprise Linux 7 - x86_64                        8,411+66
>extras/7/x86_64                           CentOS-7 - 
>Extras                                                       128+53
>updates/7/x86_64                          CentOS-7 - 
>Updates                                                     2+1,320
>repolist: 17,233
>[root at goat ~]#


I use priorities, as follows:

1: base
2: centosplus
3: updates
4: extras
5: cr
6: contrib
7: epel

Can anyone explain this?  or let me know how to get around 
it?  Rebuilding the server from scratch is definitely possible since 
this is a test environment only.

Thanks

David