Anything not coming from WFH is considered Old/Village Hung Kuen.
From what I've researched every major Hung Gar Kuen practitioner has also trained in these branch styles/systems.
For detailed info I'd contact either Yee chi Wai Directly at
"To speak to Master Yee directly (English), call 011.86.750.566.6901 between 4PM to 7PM EST (New York time). Alternatively, call 011.86.132.3294.9596 (English)."
He's always been open to his styles history and deelopment.
Also ask about Yuen Ling's Dog Boxing experience as well (link to the HG Ground Fighting thread).
If you can't contact him then i'd spead to either Pedro Cepero or Hal Asbury 2 high level seniors who also have deep knowledge of the styles history and development.