Most TCMA teachers teach students forms. The teacher then explains the application. This approach has a problem.
In the following longfist San Lu Pao Quan 三路炮拳 at 1.18 - 1.19. There is a groin kick, face punch combo.
http://www.youtube.com/watch?v=mLnVHNGsSno
It follows the kick low, and punch high principle. The form creator may assumed that his opponent dropped down leading arm to block the kick. He then punches at the exposed face. What if his opponent raises his leg to block the kick. Since his opponent's arms may still be on guard. He should add a left hand move to open his opponent's guard before he can punch at the face.
Will most teachers explain both cases during form application? What if the teacher only cover the 1st case? When will his student learn the 2nd case situation? Wait for another form that cover that situation?
If you teach how to use a groin kick to set up a face punch, you will cover all cases. You don't have to be restricted by a form that someone created long time ago.