We all see in several Wuxia novels about people learning several different and powerful martial arts skills.
However are any two (or more) of the various martial arts in the Wuxia genre uncompatible with each other? What I mean is are there any combination of different martial art skills, if studied, would not agree with each other?
For example, for the sake of argument we assume that a hero has learned a very powerful skill (e.g. 18 Dragon Palms or 9 Ying/Yang), but cannot study another skill because they would have a negative effect upon the learner instead of any extra benefit. Is there any such combination of uncompatible skills?