Hello ! Unfortunately, I had to realize that the traffic in the scenarios and timetables on all routes does not correspond to the actual volume. maybe it's not really possible to represent every train, but a little more traffic on the tracks would at least make the simulation look better.
They do use the realistic timetable but like you mentioned, other trains need to be included to make the route buster, otherwise it would just be unrealistic. If the trains look very similar to each other then fine. But if it's completely different looking trains, then I wouldn't like a fake train to run it.