Why do you need redundancy between the HMI and the PLC?
The redundancy you are specifying only covers the CP card itself (which should be very resiliant) and the ethernet cable, so I would presume you would run the two cables a totally different route, as cable redundancy is installed to protect against damage to cable, which is normally caused by something cutting through it, so running them together would be self defeating.
But why make such redundancy? Redundancy is normally to protect the process, nice to have redundancy to the HMI but in most cases the HMI can be overidden by the tech's to get things moving. Its more common to have redundancy for the PLC and the process I/O.
Perhaps that is what gregoryg was referring to?