Reno
Yes I first heard this around 1999 or 2002 from Jim Pauley at a code update seminar. I am not sure when the language changed but you do consider that all the service and one assembly.
The real reason they used bonding bushings is, this is all in front of the service disconnects in the cans below the gutter.
Up to six, you could do this and not have that line side disconnect. The real issue, I think you will run into, is accessing fuses there. That will be up to the PoCo but I bet they want to seal that cabinet.
Harold, I am not sure about the rest of the world but in Florida they want a rod at the trailer itself if it is not up on wheels. Usually that is somewhat redundant since there are also anchors screwed into the ground every 8-10 feet around the perimeter and bolted to the frame but they are not "electrical equipment" so we can't see them. They do worry about lightning hitting these things and want them grounded locally.
