Striking scorpions is the slowest ifantry unit in the game when they are not under fleet of foot. Only "On the hunt" gives them acceptable movement speed. This makes them really bad off-cooldown on "On the hunt". They cannot catch up to regular tac marines in combat and really everyone can kite them. They are a meele unit and should at the very least be as fast as a normal shooting units when they are not under fleet of foot.
Increase the movement speed to be on par of tacmarines(Without tireless). Reduce movement speed buff from "On the hunt" if the bonus is too much. Banshees are fast enough already and benefit most from the damage buff and invisibility.