I'm not a farrier, just a horse owner... and my instincts would be the same as yours, I'd think they'd catch a toe more often when they are long.
~But~
![Confused](images/smilies/confused.gif)
gaited horse show people put big blocks and appliances on feet to get them to lift their feet higher. In a sense, The horse over-reacts to the weight and their movement becomes exxagerated.
Least, that's what occurs to me. Perhaps there is something about long toes that works better when a horses is gaiting.