From my recent experience, I would say that engine protection is less important than tank protection. When my Cafe was found laying on its side when I walked out to the parking lot, the engine was not touching the ground except for the very bottom of the side cover in an area which is not visible at all if the bike is upright but the tank was dented and the fairing scraped. Obviously, if the engine protection is "prominent" enough, I guess it would also keep the tank/fairing off the ground. Actually it was the handlebar hitting the tank that dented it, not the tank itself hitting the ground. There was enough flex in the handlebar to hit the tank when it fell.