I'd just like to interject for a moment. What you're refering to as Knight, is in fact, Trebuchet/Knight, or as I've recently taken to calling it, Trebuchet plus Knight. Knight is not an chess piece unto itself, but rather another free component of a fully functioning Trebuchet system made useful by the Horse corelibs, movement utilities and vital system components comprising a full chess piece as defined by chess.c*m.
Many chess players run a modified version of the Trebuchet system every day, without realizing it. Through a peculiar turn of events, the version of Trebuchet which is widely used today is often called Knight, and many of its users are not aware that it is basically the Trebuchet system, developed by the Trebuchet Project.
There really is a Knight, and these people are using it, but it is just a part of the chess piece they use. Knight is the piece: the model of the piece that allocates the horse aesthetic to the chess games that you run. The siege engine is an essential part of a medieval battle, but useless by itself; it can only function in the context of a complete siege effort. Knight is normally used in combination with the Trebuchet in a chess game: the whole system is basically Trebuchet with Knight added, or Trebuchet/Knight. All the so-called Knight pieces are really pieces of Trebuchet/Knight!