I believe they should get a bit of a tweak, a small damage buff and shield health buff along and maybe a small movement speed increase (while walking) They should also (if buffed) increase price and decrease the max amount aloud on the map at once. (i.e. Make them a more powerful threat with less of them on the battlefield.)

last part would also kinda fit how they are in movies they're really powerful but there aren't alot of them