for anyone who has sprinted its pretty simple
the speed strength and endurance needed to run a fast 400 allows a person to come down to the 100 and utilize the speed endurance and proper sprinting form.
look at colemans form in the 100, its garbage and destine to blow a hammy.
43 speed means 10.9 minimum relaxed sprinting the whole way. doesnt take much of a genious to see that hmm im going 10.9 average, which means i can prob hit 10.2 without any changes if i was to go all out for a 100. so he was a basic 10.2 guy who then worked on it, and im sure in a few running start practices he hit 9.7-8 and thats when it was like "oh sh*t!"
a 45 mid guy is averaging 11.25, so they are a basic 10.7 so it doesnt make sense for them to drop down