I have seen rude and ill mannered trail behavior from all groups. ATV, 4 wheel drive groups, hikers, equestrians...........etc.
The worse is Jeep guys against Toy guys against FORD guys.............. I usually wheel with a variety of different vehicles, but if you get you nothing but JEEP or TOY guys they can be overly rude.
If I am in a big group we run slower, usually let the smaller groups by including all groups.
Trail Etiquette uphill has the right of way....................but it will also depend on manners, 1 person going uphill and 8 people coming downhill. It would be easy for the 1 to back down and let the others go by.