Hey guy b,
I honestly don't know what you're referring to, because in my clips I show my students actually sparring (moving freely) against non-wing chun guys.
In this clip, for example, one of my students goes 12 rounds with two (experienced) friends from the local mma gym who are preparing for a competition:
https://www.facebook.com/sean.wood.9...5459715308979/
And in the other youtube videos there are also long sequences of free sparring against opponents who are unconcerned with any type of face-saving etiquette (actually trying to knock your block off and/or take you down and submit you).
Now of course there are problems, both strategic and technical, that have to be ironed out in order to improve my student's performance. But at least we are working on it in the "lab" of real, full-contact sparring against un-cooperative opponents.