done a bit of travelling on my own, with only a couple of cars and in a large group.
have also seen the effect of groups of friends travelling together for more than two weeks ... they invariably don't talk to each other when they get back [sorry to say but it is true that this mainly happens when women are in the group]
Perhaps what you could do is to arrange to all meet at Tibooburra at the little national park camping area called dead horse gully on a certain date.
then travel to cameron corner and meet up again the next night [there is a couple of ways to go]
then meet up at innamincka the next night [there is a few different ways to go]
then all go out to coongie lakes [its all one way in and out]
etc etc etc
there is a couple of different ways across the simpson but it might be better to stick together on that section for safety if its only a small group.
anyway, the idea is to spread out a bit and have a couple of options on which group to travel with to avoid personality clashes and the whole experience should be a very happy one and one which you will always remember fondly.
One of the biggest dramas i have seen is having a definate timetable and some people blindly sticking to it and some wanting to spend extra time at something interesting so its advisable to have a loose itinerary of where to go but do not plan exactly when you will be there.
A lot will also depend on the vehicles that are going ie: to cross the simpson you need fuel for 600 to 700 kms at double your normal fuel consumption.
anyway ... here a link to a trip i ran back in 2002 across the simpson desert.
http://www.bigred4x4.com/simpson-desert ... rip-report
http://www.4wdlinks.com.au/albums/simps ... .sized.jpg
http://www.4wdlinks.com.au/albums/simps ... .sized.jpg