First of all, tanks of medieval warfare is a phrase that experts like Maurice Keen, Richard Kaeuper, and Richard Barber all use to refer to knights. Also your references to antique cavalry are invalid because they exist prior to the medieval fantasy setting of Warhammer and to the introduction of the stirrup to western armies. As for malmuk and cataphracts, they are heavy cavalry still even with their missile capability. And knights would not engage in those tactics you’ve stated. Or if they did, as it’s impossible to account for all historical instances of knight use, it was a very wealthy aristocrats for reasons I will not be explaining here because it detracts from the argument to go on a tangent like that. There is so much misunderstanding to unpack in your statements it would require it’s own post