Did I say anyone there had 'great skill'?? No. This is basic stuff but it's from a very advanced idea specifically for Wing Chun students to use as a 'training tool'. Actually if you really want to get into it, it's specifically designed for the Sifu to use to pass on the knowledge of entry and sansau techniques! Not for student-to-student practise at all.
I don't think I have ever said that it will help anyone fight either, but can see where you're coming from. But FWIW it will help and does help those who make the fight theirs and use what tools and methods they have drilled against people that may be unfamiliar with such an approach...
Just an idea but have you got a clip of yourself training some Wing Chun?