With this setup, dynamic retrieval order matters more than theoretical seating
A 9-seat van can create the illusion that any five-person group should simply keep every row for passengers.
But once hard camera cases, a folded wheelchair, medium-large suitcases and day-use gear all travel together, the expensive loss is often repeated re-layering at every stop.
Camera cases and the wheelchair both need a fixed zone
Hard camera cases do not sit well at the bottom of a stack, and the wheelchair should not be mixed loosely with jackets, snacks or soft bags.
A dedicated back-row buffer often shortens many daytime stop actions at once.
A luggage row often protects both the aisle and the hotel-unload order
When everything is forced into the boot and footwells, aisle usability and evening unloading order are usually the first things to collapse.
One fixed luggage row makes it easier to separate hotel bags, camera cases, the wheelchair and high-frequency small items into stable layers.
The back row should return to passenger use only when access pressure really drops
If the heavy gear becomes occasional rather than constant and the suitcases lighten, using the row for passengers becomes easier to justify.
Otherwise the route often trades one low-value seat for a much messier vehicle.