For the 166 the stop set for short workings is a subset of the full set but the majority of journeys do not serve the stops west of Banstead. The majority of journeys would serve a shorter list of stops. But that’s about what happens, not necessarily how the data are presented.
If you look at the 605, each of the afternoon journeys starts from a stop not served by the other, so that may be a better test. Others that spring to mind (because loops are omitted at certain times of the day) are the E7 and U2. The B12 is a weird one, as it reverses direction round the Joydens Wood loop in mid-morning!
We may be at cross-purposes though, particularly as I am not familiar with the tube sources that you are making comparisons against.
The vast majority of routes are absolutely bog standard - everything runs end-to-end, no scheduled short workings, no bifurcations. A complete contrast with much of deregulationland. I suppose it is to keep things simple but I do wonder sometimes whether it is as much to keep things simple for the electronic systems as it is for the passenger!