Not sure about Shau Hung Chan, but ...
I did look up some info on Ching Yeung (abbot of the Wah Lum temple who taught Lee Kwan Shan). It was sketchy, but did say that CY was a stick fighter with the secret society and knew a Shaolin stick form.
Implications? Well, other martial artists probably took refuge at Wah Lum around the same time, so CY could have picked up some additional skills. Also, I wonder if I Ho Chuan drew members from different MA styles, or if they all studied the same system?
As far as Southern influence -- I think Hua Lin said that Master Chan's family style (Mok Gar?) is southern, and Wah Lum has a close relationship with Lee Koon Hung Choy Lay Fut. So perhaps much of the southern flavor is 6th generation forward?
Good thread, JS, thanks for starting it up.
Sam
There is a great streak of violence in every human being. If it is not channeled and understood, it will break out in war or in madness. ~Sam Peckinpah