I have a medium wheelbase, medium roof Transit Crewcab and it easily takes 6 bikes in the back, top to tail with nohing removed.
A SWB would need the front wheels off or some creative arrangement inside.
The photo doesn’t match the description, pic is a LWB high roof but the description at a guess is a mwb low roof.
Weight can be more of an issue, 6 big lads plus bikes plus kit plus full tank of fuel and your close to VOSA having a fit in a 280.