It doesn't really work like that. You can get to your 7.5h a variety of different ways, including having a good start, but low top end speed or a terrible start and high top speed. The latter (high top speed) would mean the last 40m would be much faster than the other guy who ran 7.5h with a good start, but low top end speed as he is coming into the last 40m at a higher speed already.
