The queen is there. It was probably a more interesting game to keep the knights for their moveset rather than keep the bishops (given the need to reduce to 6x6

The queen is there. It was probably a more interesting game to keep the knights for their moveset rather than keep the bishops (given the need to reduce to 6x6). Between the ~half-sized board, the intrinsic limitations in where they can go, and the reduced pawn movement, bishops would be very clumsy if left in.