Palpatine: He uses Force Lightning, this speaks to a level of incompetence. After all, most villains have Force Storm when they can grab it. (I know I grab it, even when I'm playing LS) FSrm is a very handy power, if you can wound the others around you enough, and then use it, the enemies are dead.
Compare that to the Emperor... if anything he was using Force Shock, since he was using it only on one person. He was causing Luke pain... he almost killed him with it, so it could be said that Lukes VP's were far too low. (Low Con anybody?)
You are taking gameplay mechanics far too literally. There's no real difference between force "Shock", "Lightning", and "Storm". It's just lightning.
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