While my SO and I were practising JWs more than 15 years ago, I noticed some JWs always wanted to do 'Return Visits'. Not sure how they obtained those Return Visits since that was all they seemed to do after meeting with the group.
The times we actually did go D-2-D while in a small town with plenty of rural territories, many JWs insisted on calling on an in-town home nearby to the 'rendezvous' location so everyone in the vehicle could start their time before we all drove to the farthest location within the territory.
After calling on a few rural homes, it was then time for coffee so after spending considerable time in a restaurant, it was then time to either drive to the opposite end of the territory for a Return Visit, or drive back to town to call on one more home so as to stop our time before each proceeded home.
If 4 people in one vehicle, 2.5 hours with the clock running = 10 hours reported while calling on maybe 6 or 8 homes.
With these examples, it would not be surprising few JWs would be seen while many hours continue to be reported.
I observed a group of JWs recently distributing invitations to the memorial. Although a simple task, the elder in the group appeared to be somewhat overwhelmed by his own doing. With his important and heavy responsibilities, he seemed to dictate even simple activities of the others and each appeared to be required to frequently report to him which homes they had called on.