Special end over 80-100m not as high intensive as sprint over 60m

One chart at the Vancouver seminar 04 shows the classification of training elements:

high were:

1 high: sprints <9 sec / maximum weights
2 high: plyos / special endurance 1+2
3 high: strength endurance / lower weights

4 low: tempos

Of course its mainly high or low…

But: to monitore and watch for te feeling and plan well(i.e. in terms of comp) it is useful to have the classification in mind.

The best example is the split routine in the GPP:
It makes sence, bc hill work is high, but not as high as sprints(categorie 1).

My question:
Why is special endurance type 1 not as high as sprints???

For SE II its quite clear; not running at 100% velocity. But at SE I(i.e. 80m) i start as fast as over 50m. So there are the same intensities over the first 60m! I just deaccelerate after ~8sec - all right, but what about the first 8 secs. Isnt it categorie 1 ???

For SE II , i think its clear. You arent going all out and run at ~98,9%

Any ideas about SE I ???