I wonder how much of an advantage the rule "a knight cannot land on a square which is under direct attack of the opponent's knight" gives to black. White has to place his knight first, and if black places his knight on the same coloured square as white, black will never be "blocked" by white's knight, while the white knight might find squares unavailable to it because of the position of the black knight.

Of course, if black puts his knight on a square of a different colour, white gains that advantage, but it's up to black to do this - white cannot influence it.