Greetings.
Geezer, upon thinking of making a topic about this, I pondered the effects of such an idea... and my thought experiment revealed that it could be taken as flamebait and could start a flame war, troll bait, etc.
The question of this topic is answered by "it depends". Wing Chun has butterfly knives (less than 12 inch blades), and not butterfly swords (about 15 to 18 inch blades or more). Also the WC blades are thinner with much less mass.
Obviously, this change in category of mass and length has significant impact on the tactics and strategies involved.
For example... if I have 2 baat cham dao against a 6 1/2 pt. pole, would I use the tactics practiced traditionally?
No. I would probably throw one and close the gap to neutralize the effective range of the pole (possibly grabbing and pulling on the pole with my now free hand) and then poke at the hands of the pole wielder and do as my objectives dictate.
Also, what sane person is going to attack unarmed a guy with 2 kung fu looking knives (or any knife, for that matter) on his hands? If the weapons are readily seen the person with the knives just stab and slashes a bit an it is done... something that is so rare as to be statistically non existent...
If one has a knife and the other doesn't, normally it is attempted murder. And the attack is to be as stealthily delivered as possible, since the point is to assassinate easily, not having someone resist.
If both are armed and want to go at it, it becomes fencing.
Thus the question is... what is the purpose of training using drills that develop certain skills that have limited scope of application, compared to other drills and skills that have wider use, are simpler, and go better with the principles of the philosophy of Wing Chun?
As said by some warrior of the past... Do nothing that is no useful.
Anyway, if my reasoning has fault, please let me know specifically how so, so I may experiment and reach conclusion.
Hope that helps.
Juan Mercado
P.S. I train weapons once a week or every 2 weeks. This includes firearms, blades, batons and impact weapons, fencing for fun with similar or different weapons, and every once in a while, kung fu weapons. I prioritize time in order of what is most probable and requires more training. You do the math.