Another gem from Sharkey:
“The Harrier's success was due to its great manoeuvrability and our sound training.”
From my experience the Harrier was a poor combat manoeuvring aircraft because of its high wing loading and low maximum speed.
However, if the opposition aren’t making much effort to avoid you (basically because of lack of training), then you don’t need much manoeuvrability - or skill - to get kills, especially using a magic piece of kit like the 9L.