Yes, I have Parquin and de Brack both, though it has been a while since I last read them.
The Austrians, Russians, Prussians, and British ALSO had trumpets, but somehow those instruments apparently failed to result in massed cavalry charges :o)
I am curious, when Mad Micheal decided to charge at Waterloo, any idea of how much time it took to organize, how many aides or couriers carried the orders from Ney to the various commands, how long it took division or brigade commanders to send on to their subordinates, or the extent to which any details of bearing, points of advance, who was to support whom, or objective were given at any of the command levels? I admit right off, I haven't a clue.
My blind bet is that nobody told the regimental commanders much at all, and squadron leaders probably got next to no news but that the unit was advancing to the charge. But I don't know this for a fact. Do you suppose that rally-points had been determined early in the day, were assigned by the orders carried from Ney, or were never identified (which would have allowed for plentiful confusion after a repulse as each troooper or company or squadron tried to locate where its regiment was reassembling...those trumpet calls agin!).
I suppose that a point you made earlier might provide partial explanation: the SOPs that inevitably arose from time spent together. I have no idea of the extent to which the units of the reconstructed army had a history of past association in their order of battle in 1815. Yet, certainly their officers and generals had experience and habit of usage to draw upon.
What do you suppose inhibited the Coalition armies from using massed cavalry action (well, okay, the British didn't often have two brigades to rub together, but what about the Russians, Austrians, Prussians)? There was no technological limitation, they had similar tools of drill, and they all had historical experience of the use of massed cavalry, at least during the Seven Years War and earlier.
Curious - Howie