If you want to get fancy, why not bolt a small bracket to the ground, tether the cones to that, pull a string and bam, cone is back in the right spot. :P

Jokes aside, the marshals have done well to manage to risks running onto a live track to reset cones. I don't see there being a large risk because the marshals are aware of the hazards and can choose to wait until they have sufficient time to do it. Big tyre stacks and walls will just make the situation more dangerous for the drivers. Its just moving the problem onto someone else.