I don't see how setting up MIT or Heimdal Kerberos is complex compared with AD (which is more than Kerberos); they seem easy enough to me. SSO seems to me what

I don't see how setting up MIT or Heimdal Kerberos is complex compared with AD (which is more than Kerberos); they seem easy enough to me. SSO seems to me what you want, and Kerberos is the reasonable implementation.