Gooner_mike, I think you're underestimating how important those fixings actually are. It isn't just the end points that provide the 'anti roll', the forces are applied equally between the end points and the beam fixings.
Consider that an ARB is designed to resist twisting forces, the end fixings aren't sufficient to resist twisting. If you only had the two end fixings and lifted one side of the car, you'd see the ARB move out of alignment with the rear beam. It's that twisting force that you're trying to eliminate.