NPE, welcome back.
I am not a sprint guy and am guessing here. Some of the things you do the make the first part of a race faster make later parts slower. This is almost trivial in that running 50-flat for the first 400 of a 1500 will not get you to the finish faster. As you shorten, things get a little less clear.
It is my opinion that going REALLY hard for the first part of a 200 takes a toll in the second half - it seems some sprinters agree and some disagree, but even here the nature of the curve adds a complexity. [I think that Bolt said that he feels like he goes just as hard, yet he hits nowhere close to 9.5x for the first 100 and I think that not all of that is that the track curve makes his 9.58 effort and turns it into a 9.8 or 9.8 (cannot remember the split) time.] Even in the 100 people are tie up before the end and if they went that hard the first 100 of a 200, they deceleration would be greater.
Going down to the 100, does more 'effort' in the first half translate into speeding the 100 up (e.g., 0.05 fast over the first 60 leading to 0.05 faster over the 100) or having to give back a little of the gain in the last 20 meters (0.05 fast at 60m leading to 0.03 faster at the end). The third alternative is that they are outright faster so that 0.05 faster at 60 leads to, so, 0.08 faster at the end. In addition, being faster due to better reaction time seems like a pure shift which carries through to the 100.