Kinda hard to stop trucks from showing up...
I vote 2 groups, if we get more than 10 trucks to actually show up on 14 September. That way the lead group can have beers and dinner ready, my tent setup and my pillow fluffed by the time I pull into camp with the second group.
So, I don't want to over analyze this, but I will, so here goes:
6-8 trucks with experienced/competent drivers in a group for a trail like this is not a bad thing; if planned properly with respect to tools, spares, kitchen supplies and food, loads can be spread among the group. Not everyone needs to bring their own full set of tools and full arsenal of recovery gear pieces. There is a balance between being prepared for breakages and overloading to the point of causing breakage. Once a mile into the trail, it is not really feasible to run back to the parking lot to get your spare from the back of your tow rig.
A group this size allows the group to be able to split up based on skill sets (or lack there of). Disclaimer: My position is that the ultimate goal is to keep the group together as much as absolutely possible.
If someone is admittedly not mechanically inclined or does not spend a lot of time wrenching, they are probably not needed in the repair crew. In the event of a breakage that requires a trail repair. If the breakage is late or is going to take a long time to repair, those with the food and kitchen gear or gear can be swapped so a group can roll ahead to camp and get their junk set up while the other half effects the repair.
Another thing to consider is to factor parts interchangeability into the equation when organizing the groups, if we decide we need to do break into 2 or more groups. Though, I don't think that will be necessary. As I count the responses in this thread, there are about 14 folks who have expressed interest in driving their rig on this trip. Do you think we'll get more than 10 actually on the Rubicon in September.
Just some of my thoughts; you get what you pay for.
All that being said, I'm in.