The upshot is that in the first case the enemy will be hard put to dislodge an advance guard and attack the main force, all on the same day, as experience tends to bear out. Even in the second case the enemy will have to dispose of the advance guard before noon in order to have enough time for the main battle. Since in the first case night comes to our aid, it becomes clear that much time can be gained by posting the advance guard farther ahead.
