Good post. My WC might not look like the other guy's therefore it sucks?.. . . lol.We can only speculate, but I think some of the weapons were likely individual inovations rather than being part of a particular system. Some might have even developed entire fighting systems around a particular weapon. And being that the powers that be at the times did not allow their citizens to own or carry weapons, they had to come up with the use of common items or tools as a substitute. As for the pole, the monks often traveled and they had to deal with bandits as well as large wild animals. A pole would be a good weapon in such cases, especially if the monk had some sort of fighting form with it. Just poking at something might work, but it works better if you have some poking skills.
As for Wing Chun, I think that it had a great deal with who the practitioners were and what they had on hand. If you lived on a junk and a long pole was your tool for helping move it about, then it would only seem logical to learn other skills with it. After all, they had likely seen the poles used elsewhere. And the knives? I can imagine that they evolved as weapons because they were available as well. The acrobats did lots of dance and stage play stuff, and butterfly knives were commonly used in these productions, so why not learn to fight fancy with them? It all comes about through need or oppertunity. When Wing Chun came out of China it brought it, traditional forms and weapons. However, just watching people from different lineages do the SLT you can see that there is a great deal difference from one to the next. At the time WC was being taught and used in daily life, it probably did undergo lots of change time and again, especially as it went from one person to the next, but they were probably not so fixed on traditional as it is today. Probably more concerned with making what they had work for them under the current circumstances. Westerners go to great extent to try keeping things as traditional as possible, even to the extent of learning the language. You hear all the time people saying things like, that isn't WC, or it don't look like WC, or WC don't have that. Well, as long as you can follow the basic concepts it is WC.
LCP
Most intelligent martial artists don't think this way.