I understand why there are margins buddy, and 15% is a pretty good margin. But seriously, if you can’t land in 167% of the distance that they worked out in flight testing, maybe it’s time to go back to flight school.
Those figures are off the Maximum Braking performance of the aircraft which you couldn't realistically use every sector as you would scare the pax and burn through parts. We're talking a carrier landing followed by standing on the brakes to a complete stop.
The real margin on 'normal' landing performance is much less than that as noone ever lands at maximum braking. Hence the 15% figure.