That the thing not many if any rock types are viable in hackmons simply because of the weakness to mm2x and arrows being crucial. Also most of them have really bad special defense and while you run sandstorm for that you also hurt your other mons with it. Also remember that there is no more permaweather which makes sand a hella less viable. Also pretty much all shedinjas on the higher ladder are safety goggles. I thinkIt was just to give me a surefire way of beating Sturdinja and it was the highest BST Rock-type which doesn't require Multitype, so I just gave it Sand Stream and Knock Off.