Harminder.
You are right that jhoomer, dhammal, ludi are dances on their own, but you have to realize that when they are incorporated into bhangra...they totally look different and adapt to the style and pace of bhangra routines. If you ever watch bhudde babbey do those original folk dances, you will see how different it is from when those dances appear in bhangra. Just look at gabroo shokeen`s jhummar exhibition vs. what most teams do for jhummar these days. So, to be honest, folk dances actually are part of the standardized bhangra style that is now the norm after partition. Without this standard, bhangra would just be the fun, but not stage presentable, dance it was in the pinds.

as for the claim the traditionality cannot be entertaining or even different, watch this video. you will see how they flip and rethink traditional moves to separate themselves from the masses: http://youtube.com/watch?v=UfJ0uJAGIqE&feature=related