I was taught archery, in the mid to late 1950's at my prep school by a man then in his late '80's, using a Victorian yew longbow. He always insisted that the index finger on the draw hand was above the nock of the arrow, not all three below. And like you we used a pin as a sight, moved up and down and sideways (according to windage).
As to the "two finger" V sign I have added this from Google:
......pleased to discover a PDF version of Wavrin’s chronicle, hosted by the quite wonderful people at La Bibliothèque nationale de France. The quote that seems to have started this whole myth; appears in the English translation (found in the Fifth Volume of Book One – page 203 of this PDF document) as follows:
“…And further he told them and explained how the French were boasting that they would cut off three fingers of the right hand of all the archers that should be taken prisoners to the end that neither man nor horse should ever again be killed with their arrows. Such exhortations and many others, which cannot all be written, the King of England addressed to his men”.
Whilst the Middle French original reads like this:
“En oultre leur disoit et remoustrait comment les Francois se vantoient que tous les archiers Anglois qui seroient prins feroient copper trois doitz de la main dextre adfin que de leur trait jamais homme ne cheval ne tuassent. Teles admonitions et pluiseurs autres que toutes ne puis escripe fist lors le roy d’Angleterre a ses gens.”
So maybe we should be waving three fingers at Johnny Crapaud!