Obviously, each kid comes with a certain set of skills, strengths, and weakness. Personally I start with 400 type of training and then move the kid to 100/200, 400/800, or 200/400 type training. In my program I have found none of the issues with using a Hart like model with my sprinters. Most of my kids run their fastest times at the end of the season and also the end of their career. What you want to see is the trend of improvement you will never completely get every kid to peak in the last race 100% of the time. This comes from a large number of factors. However, you should get close to a 75% number trending to the fastest performances at the right time deeper and deeper into their career. If you were to go on Mo.milesplit.com and look up our top performers from the last seven years you will see these types of trends in most of my kids in all 100-3200 and in the triple jump. We have had a number of relays finish all state along with a number of sprinters, hurdlers, and distance runners. The fear of doing 350s, 400s, or 450s to me seems silly from what I have seen in my 11 years as a high school coach. In fact both of my 100 meter dash runners up in our state championship in the 100 Lewis 2003 and Jacobs 2008 were trained with a long to short method. Of course I probobly use more acceleration and short sprint work concurrently then a guy like Hart. However, I also am not afraid to make our special endurance work the main workout of the week. I also believe in not running the same workout week in and week out even in the same cycle. These workouts should have the same theme but the distance, rest, volume, cues should change slightly to keep your athletes attention.
"Nature hides her secret because of her essential loftiness, but not by means of ruse." -Albert Einstein