One of the reasons the BAe 146 gets a reduced Landing Distance Required for steep approaches is because there is less statistical scatter of touch down point, and therefore of achieved landing distance.
At LCY however there are touch down cut off lights, i.e if the wheels are not on the ground by the lights you go around. Threfore pilots make a big effort to touch down before the lights.
When evaluating the stastistics of touch down point this may account for some of the reduced scatter at the upwind tail of the distribution, i.e. the reduced scatter may not be due just to the steep approach.