WHY IGNORE THE MUD?
WHY IGNORE THE MUD? It’s puzzling that knights would choose ground that negated their advantages. I wonder if the emphasis on single combat for knights led them to ignore tactical considerations. Jousting took place on level ground and the rules confined the movements. Courage was critical. I doubt that the use of mallets occurred to chivalric warriors.
It isn’t quite on point, given that as you say, knights had more of an individual sensibility than modern soldiers/armies might, but Union generals in the American Civil War repeatedly took engagements on bad ground in the war’s opening years. Sometimes it’s just a mistake.