Detriment is 36 elmos/s scorpion is 39 ,scorpion is the only unit in the game that gets hit by impaler while moving thanks to its abysmal speed and widest hitbox in the game.to add more insult to injury it has same hp as cyclops a unit that is much faster at 57 elmo\s and has auto targetting slowbeam.
For a unit that should be invisible it really does not take a genius to know that the scorpion that he saw 15 minutes ago is probably just now reaching a repair station.
Its cloak only helps the frst strike which is very difficult to pull of because youre effectively trying to ambush units that can move with a building