Don't have a scorpion but have some AR15 pistols.
For me, the best reason for a hand stop is to keep my fingers/hand well behind the end of the handguard/free float tube and the end of the barrel. All of mine have either a magpul handstop, or something similar (aluminum, but looks/works similar). They aren't real big, but they give me a stopping point when my hand goes out towards the end of the free float tube.