I don't think they have zero route knowledge, the few European drivers I've spoken to before still have fairly specific route knowledge and don't tend to work off route. For example NS International high speed drivers sign Thalys and Eurostar e320 and work Amsterdam to Brussels with a few diversionary routes via The Hague and the classic route.
Depots tend to have their own routes over which their crew work and they do not need to know the routes that much to work them.
Working in Germany many years ago I spoke to drivers from Germany and Poland ( my job involved travelling between these two quite often ) and they only had to do few day and night runs to familiarise .
The rest was down to signalling and information given in a book / sheet that had the timetable of a particular train, almost like schedule(s) card book, that was called “crew timetable “.
In addition to the “stopping” stations arrival / departure time , there would be stations, where they did not stop with passing time .
That schedule would also tell all speeds , and where they apply ( hectometre / kilometre posts ) .
I was also told that, they could drive any route in emergency , providing that they would not go faster than ( I think 25mph ~ 40km/h) .
They could do that as the signalling was this same everywhere, it had this same meaning , and the only thing that could be “thrown at you” was, that you would be required to be crossed over from one track to another , and default speed ( lowest ) was 25mph .
Their drivers would also not be penalised for “wrong routing “ as the signals would not tell you , which way you were going before it was too late .