Same here and can confirm the scoring is up to the teacher.
Shovel: Neutral-Good (farming), Uncontrolled (it’s very unlikely you can do much harm to society with a shovel)
Backhoe: Neutral/Good (efficiency), Controlled (heavy machinery can easily kill people and damage infrastructure)
Agent Orange: Bad (imprecise, damaging, disease-inducing), Controlled (considered a chemical weapon with no legitimate societal use)
So I think that more oversight should be used in order to prevent teachers with bad and abusive efficiency strategies from, for example, downvoting children for needing to pee.