I pose the question as stand up art how can we better judge a person's ability without damaging eachother.
This is really simple, you spar... Throw on some shin pads, 16 oz gloves and headgear if you like and go at it. Even going at a hard sparring level no one is getting hurt, and it is very obvious who has skill and who doesn't.
People that do striking arts and don't do contact sparring tend to overestimate the damage a hit causes. I've met many people that, if they where correct everyone that entered a Muay Thai, MMA or Kyokushin event should be crippled for life