I think that long par 3's do favor the shorter hitter, here is why. As a low handicap player that hits it long enough, but not super-long or anything, when I come to a long par 3 and have to give a shot, I realize that I am very vulnerable, because if I hit first and miss, the hole is most likely lost. When a hole is very difficult, it lessens the longer players advantage, because the distance advantage is only being used over one shot instead of two or three, so it is all about math. If they both miss the green, chances are the shorter player has the better short game, if he doesn't, then he would be getting a shot and have an even bigger advantage.