here is a fight between two Muay Thai fighters who engage in quite a bit of clinching and watch the ref. Especially if the clinch is against the ropes.
Scoring in Muay Thai has often been a contentious subject as. Read this to learn Muay Thai rules and scoring to appreciate the sport.
www.muaythaicitizen.com
It does take awhile to get a feel for it. It goes against the western combat mindset. I think punches should count for more but I understand why they don't unless they are affective and not just 'activity'. Remember this. A fight is judged in it's entirety. Some bouts are actually so hard to score. you can also google muay thai judging and read some articles.