I do not believe the Ground Vehicles have a matured physics model. If you pay attention in the way that vehicles sometimes roll over and stop upside down then roll upright after several seconds you will know what I mean.
The GVs appear to be using flight models that have been modifed to represent ground physics. I also find that the way the damage model acts on GVs is poorly adapted. If you have ever hit an M3 center of mass with an 88mm cannon at 200 yards with LESS than 30 degrees deflection and ricochette off only to watch the M3 speed away unharmed then you know at I mean. There are issues there.
In these ways I feel a GV only arena is premature. But, if the casual gamers like it, and there is enough interest in it, then I do not see why it wouldn't work.