This ties directly back to the OP, is Wing Chun being used wrong? Myself, I feel that Wing Chun is a specalty method of refinement while others believe it is a stand alone all inclusive method. I would argue that for the latter, it has been forced to fit that paradigm due to bandwagoning.
---I think there is merit to what you have been saying about Wing Chun being useful for "refining" another method's "gross motor skills." I'm just not sure that was the original intent or what it was originally designed for.
From my viewpoint, evidence is plentiful that it works fantastic for what it was designed for.
---Which, in conjunction with my comment above, leads me to believe that fighting "back in the day" was a bit different from what it has evolved to in modern times. For example, the emphasis on lower guards and protecting the chest in TCMAs leads me to believe that, short of battlefield encounters, there may have been a general agreement that they didn't go for the head nearly as often as people do today.
From my view of refinement, integration alone changes the dynamics. The goal isn't to refine your movement to mimic Wing Chun, it is to hone your movement, to maximize its efficiency within the parameters of your system when at close range. For this, proof of effectiveness is plentiful, the likes of Allan Orr comes to mind.
---But then, if that is the intent, why learn the entire system of Wing Chun from start to finish?
From how I see it, you can train harder or you can train smarter. Fighting should never be about styles. Names like Wing Chun or Kung Fu won't save you. Adhereing to dogma for the sake of purity won't either. Fighting is about doing what ever it takes to increase your chances of winning. If it isn't recognizable as something specific, while engaged in the action, who cares. The goal is to win the fight, not look a specific way. Its not dancing.
---While I agree with your sentiment, I don't agree about the final result. If someone has been spending multiple hours and months and years training a martial art with a specific biomechanics and way of moving....and then ALL of it goes completely out the window under pressure, then they have been wasting their time. It doesn't have to be "picture perfect" and look exactly like the forms, but if it is completely unrecognizable in the ring, then why are they practicing that martial art? Why aren't they practicing something that is closer to what they are actually doing in the ring? Wouldn't that be much more efficient? Wouldn't everyone expect that a seasoned boxer attacked by a mugger at the club one night would be throwing jabs, crosses and hooks that looked like boxing????
It is possible to teach a method that doesn't look the same when fought with.
---Then I would say that is a very inefficient method!
I have yet to encounter anyone who uses every technique they learned from the art they studied while fighting. Most individuals only use a handful of techniques in a fight or competition, ones they are competent with.
---Well, yeah! But if your martial art teaches you a specific way to move....a specific biomechanics, why would you expect to use a different biomechanics or move completely different when under stress? That makes no sense to me.