My own thoughts are that the game is best as it is here at brainking with no hostile citadels and the king always with a four man capture. The hostile citadels would make it too easy for black to place two men right beside each corner and occupy the only spaces the king can escape to. And two man capture of the king would make for very short games in black's favor.
(hide) Play a game in real time with an online opponent! For this to be possible, you and your opponent have to select the action "Move and stay here" as default and then reload the page with the F5 key! (TeamBundy) (show all tips)