Those pole methods differ in many ways. LDBG in HSHK is LDBG in YMVT, identical in theory and function, practically identical in form.
I never spoke for all Wing Chun methods. Many have changed drastically over the years to something entirely different.
I know you didn't. Just saying, it's in the OP of this thread and some other posts, and is what prompted this discussion.
Agreed.
Concerning pole methods, yes the HSHK pole is identical to YMVT as well as Kulo 3 1/2 point, probably others too. But it's important to remember that it may not be all of the HSHK pole set or that Lam Sai Wing may have actually choreographed the segment inserted into 8 Diagram pole. That would raise more questions about legitimacy of others who then have the same pattern.
I'm simply stating, knowing both 5th Brother pole & 13 Spear pole , as well as, 6 1/2 Point that they all contain the same method. 5th Brother pole is the mother. Yes other techniques are included, aside from a 180 spin in 5th Brother & twirling in 13, nothing else violates Wing Chun theory. It's not much different than comparing Tang Yik pole & Yip Man pole. Difference is in organization & repetition mostly, there are other techniques but they are cohesive. It's like comparing SNT to a version of SNT performed out of order. The order makes no difference conceptually and not justified to say it's not the same because the choreography is different.
It also has to be taken into consideration that Choy Fung Lung was a disciple of Wong Fei Hung that also learned from Chan Wah Shun. He could be the real source of Lam Guei Chung's pole method.
All of this still doesn't validate Wing Chun empty hand being based on the pole, it's interesting but not verifiable. We can clearly see the evolution of the pole from 5th Brother to 6 1/2 Point. Valid consideration has also to be given to how the empty hand method & theory could have been the reason that 5th Brother pole evolved into 6 1/2 Point and would account for mutual methodology of hand & pole.
Your premise can be applied to White Crane, in specific, 12 Branch Power Fist, being the base for SNT, as one section of that form is identical to SNT & contains the same theory. It could easily be adjusted to play exactly like Wing Chun, it's a chicken or egg thing. Very hard to prove one way or the other without raising more questions. It's a rabbit hole in my opinion, especially when oral legends are discounted because they lack verification. Buddha & Jesus can't be authenticated, they didn't leave any writings, those that came after them wrote about them, much like the Wing Chun ancestors, except their tales are far less fantastic. How could anyone dismiss plausible stories of some common opera performers, yet believe the fantastical feats of philosophers worshipped as deities? Neither case can be proven, and when it can't be, I'm more apt to believe possible vs impossible.
Just some things to consider as you move forward with this theory.