The whole idea of lifting lighter weights to tone your muscles is a myth. Toning is all about body fat.
BF% is genetics and diet. Toning is bullshit. The only thing you can do with a muscle is make it bigger. End of story. As for this endurance bullshit. That is cardio. As for lifting lighter weights more times... How many times do you think a power lifter with a 550 lb bench could bench 135 lbs? I guessing a fuck ton more than buddy-crossfit. Just saying...