when it's all said an done, the concept of 'ranges' creates an easy rule-of-thumb for begginers or people new to fighting can grasp. Like everything in martial arts, there are exceptions and adaptations to the rule of thumb. For instance, it'd be easy for me to teach a new student 3 techniques from 4 ranges (kicking, boxing, trapping/clinch, and ground) because it'll teach the student awareness of distance, and the awareness that some techniques don't work as well if the opponent is too close, and other techniques won't work if the opponent is too far, or some techniques lack effectiveness on your back. to the topic at hand, many contemporary jkd circles combine wing chun and kali trapping with the muay thai clinch, and consider both within the same range. in theory, my fight can close into a trapping range, i do the traps, and the hands are immobilized long enough for me to gain a muay thai clinch and do some real damage with elbows and knees. the other bonus with learning trapping is developing the attribute of sensitivity, where you can feel the energy of the opponent's limbs and do something very quick and smooth to counter. MMA coach Greg Nelson was known for using the hubud energy drill from kali to help him improve his wrestling, where you have to 'feel' where your opponent's limbs are going more than you can see.