A couple of those sightings of BCZ 259 attached to N 13 are on runs that are rostered for a single 3 car N set,.
As BCZ 259 has been attached to N 13 for a while I guess it made sense to leave it on there for a few gallops.
The 1213 Albury Sundays being rostered for a three car N set appears a bit of an oversight, but I guess there aren't enough 4 car sets to go around.
I would say the 0913 Shep on Saturday is a rare event to see the BCZ car attached to, but I would think passenger loading on the Albury would see it attached whenever possible.
- however as there are three remaining 3 car N sets, N 4/13/16 of which N 16 has power doors, the operation of the 4th car will not happen on this service all the time.
Car set FN 6 with BCZ 262 has been operating in tandem for a while as car set VN 12 is at Newport.