Perhaps so Rapparee ~~ but the point is that they had gone extinct some centuries and many human generations earlier, so that there had been no continuous tradition of horsemanship among the indigenous American population.

WAV ~ There were no "discomforted mouth movements"; horses champ on their bits because they are there, not because they are uncomfortable. Read the Cavalry training instructions I gave the link to above, 05.00 AM, and learn something about horses ~~ a topic on which I am no expert, but on which you are clearly entirely ignorant but full of self-righteous oh-diddums PC misapprehensions.

~M~