RNP cannot replace visual manoeuvring and dynamic trajectory changes, as much as it is a blessing of a substitute for old-school IAPs.
I wonder how many visiting pilots who actually flown there share the opinion the assistant was an obstruction in the workflow. The one I spoke with had but praise what a joint effort it was to nail it perfectly on the first attempt.
Regardless, the key point of having a guide is he'd tell you when to abandon, their most valued experience is knowing how bad is too bad in case you keep pushing...
Similiar, the CAA does not care if you divert, the not-crashing part is their concern.