I guess I assumed all scores were just percent scores based on different scoring metrics. I need to figure out where I can find information on exactly how each challenge type is scored. I'm not following your explanation on TC scoring, as I don't see how a good robot that doesn't run itself out of energy with misses would ever score anything other than 100. If the opponent doesn't fire (or hit walls), the challenger would score 100 on every round.
Okay, reading a targeting challenge page more closely, given that the challenger is only supposed to fire power 3 bullets, I guess the intent is that on some rounds the challenger will run out of energy such that scores will vary. While I like the idea of not having the opponent firing back as an extra variable, having to alter your challenger's gun to only fire power 3 bullets means this is not a full test of the challenger's gun; it's just a test of the challenger's gun's aim with power 3 bullets, leaving out distance and power controls.
I also have to wonder why the movement and targeting challenges are not just inverses of each other.