[ErichKeane]

A fuse in the shorted circuit would prevent any discharge from causing significant damage if the frame was grounded.

Vehicles are grounded because it is safe. The simplicity of the electronics system is a byproduct of running the whole body as a ground, but in the end, it is still safe enough that every car made in the last half century does it!

Why would you need a ground-breaker? I've never seen a system where this is even done before. Again, in your car, each circuit has a fuse, but the master fusible link prevents the positive line from getting grounded and causing damage.

When it comes down to it, a grounded frame would be safer. I'd rather have a short cause a fuse to break, than have the chance at harming a person. A grounded frame makes a short immediately obvious! Otherwise, it causes massive electriction risk to anyone around the battery! Touching a ground wire on the bot is fairly easy, all it would take is someone installing/removing the battery while in contact with the frame.

I also still don't see how two colliding bots with grounded frames cause any issues. Attaching the ground wire from two batteries causes absolutely no problem.