The real engineering question is: is damage to the sliders acceptable? I think we know that either will protect the rocker under typical off roading conditions, ie. not airborne and slamming into rocks etc. so the idea thinking as an engineer is to first protect and then cost vs acceptable damage. The analysis would be arbitary but the idea would to be pick a worst case scenario that the rocker would encounter and go from there. The manufacurer might be able to provide this calc if asked for it.