Shēnfǎ (身法) or body method is truly important in wushu, especially internal martial arts. To capture the essence, the ideals and principles of the art is the goal. What has been laid out to us by previous masters of old is shown through the movements and explanations of the exercises and forms. To capture their Shēnfǎ gives a student a chance (yes a chance, not guaranteed!) towards true Gong Fu in that martial art. To move without coordinated effort, inside and out, will most likely meet sub-standard ends. To reflect what previous generations built upon is the start towards mastery in your particular art. Are your stances too high? Then work on getting lower, building your base. Are you moving slow, scattered? Work on connecting your body, moving slowing at first but working towards swift coordinated movements. There is a reason for all this! Strong, agile, and flexible legs allow for greater Gong Fu! So do coordinated, swift, and agile movements! The masters of old understood this and are reasons there are amazing stories about them (whether embellished or not, there is still a reason they have stories). They worked hard to achieve great results. To attain their results one must follow in their footsteps and capture their Shēnfǎ ! Without truly understanding the moves, their methods, their applications one does not get the totality of the art. Will their art be hollow? Possibly not, as they may still attain some value whether it be health, relaxation, balance, strength, self-defense etc… but they will not gain the maximum benefit, the deeper treasures within the art. This treasure includes capturing the Shēnfǎ of the art, to work towards mastering it and all the benefits it contains.
Now can a person learn more than one art at the same time? Yes why not! Traditionally students learned one at a time. Why? Because that’s how you master something and that mastery often provided security for their families (financially and physically) and abundant health too boot! Also then they were able to more quickly learn other wushu styles and exercises. Their body was attuned to learning and had method already. It was connected and agile. It was strong and healthy. All of these reasons allowed someone to quickly ascertain another style. What are commonalities among internal arts? Qi/Lo, Kai/He, Shou, Song, etc.. These can translate to the others and make it easier to learn the Shēnfǎ . All of that being said if you have a great instructor and you work diligently in each art; you can grasp each aspect. Its more difficult as it requires constant effort to not leak into the other art but it is possible!
Now what if your instructor says all the forms and stuff is BS and they have a few moves that grasp at certain aspects of a martial art? Its their prerogative. Several great masters would learn some style completely and grasp moves from other styles to create their own Shēnfǎ . If their Gong Fu was truly special (masters like Yang Lu Chan, Sun Lu Tang, Fu Zhen Song come to mind) it would continue for generations. To say they have mastered the Shēnfǎ of that style is a misnomer though. They may have taken pieces and garnered some skill but may not reflect the style they got the movement from. At this point their martial art becomes their own, their own Pai (fist) with its own unique Shēnfǎ . At this point it would be up to them to spread their art/style, hopefully garnering enough skill and ability to continue for generations to come.
In the end your journey is your own. Do you want a more traditional path or something that is close by which might not be traditional but keeps you active and healthy (and possibly has great sel-defense qualities ;). Its your journey and you enjoy it. I will continue down my traditional path, looking to master the styles I choose and ensure I properly display each Shēnfǎ successfully and tactfully. To gain a deeper understanding of each art, to understand where they converge and where they diverge. To take these aspects and apply them as I see fit, either for health or self-defense.