The oft-repeated archery origin story for the V sign is untrue.
You could be right, but then as neither of us was alive in the 15th century we'll never truly know. Bernard Cornwell, writer of the Sharpe novels and the amazing novel about the Battle of Agincourt mentions it on more than one occasion that the V sign originated as a derogatory sign against the French. His books are subject to rigorous historical research so I doubt whether he would put something like that in them if there was not the chance that it were true. While I would suggest that capturing English Archers makes no real sense, why not just kill them outright? I'm sure the cutting off of two fingers and sending you off as a warning to others does have some merit, although cutting something else off would probably deter them further. Historians are still debating the legitimacy of the origin and while it may be dismissed as mythology, even myths have origins.
The 'pluck yew' thing is total bollocks I agree.