Honestly, I think there is rather too much certainty on this thread. The sources are deeply contaminated, since the armoured and mounted knight was such a popular figure in the literature of the age, and trying to work out actual medieval battle tactics from that is about as easy as deducing the finer points of WWI air warfare from "Biggles Learns to Fly"
I never was much of a student, but I do remember being told during a module of my history degree covering roughly this period, that the real problem was that no-one today actually knows how medieval battles really unfolded. Eyewitnesses are contradictory and frequently provably incorrect, literary sources are impossibly romanticised, and actual teaching materials are patchy due to the sensitivity and secretiveness with which they were regarded.