It doesn't realy matter. I have a big twin axle van and because we travel as a family group, we often end up puting our van across our pitch to kind of create a U shaped area so we can use the area infront of the vans as recreational space for us all. We can have upto 5 caravans in the troop and three of which are pitched as described.
Most site owners are quite happy to discuss and advise before you set up. This is most helpful to both parties and often we are suprised by their willingness to assist.
I know the root cause is, that they want a safe site with van correctly spaced, but also they want a site which attracts people too, and often variety of pitching is an attraction to others who don't want to follow like sheep.
I have a moto at work as a supervisor and that is "give a little get a lot".