This behaviour has to be related to the fact that the volume group name does not change when guests are cloned. I do not know where the confusion originates but doing xmldumps from virsh shows that all of the guests only have their own VirtIO disks assigned to them so the cross linking is happening elsewhere and the vg name seems the likely place.
However, I am at a loss as to how to avoid this. It does not appear that an option to rename the volume group is given when cloning from virt-manager. Is there a way to do this when the guest is cloned?