It doesn't matter how technically sound your running style is, if you are not in shape you will never win a race. Same goes for martial arts.
To get to a high level you need both, and you need to know how to use and when to use both.
Dismissing strength and athleticism is as silly as dismissing proper technique IMO.
But to answer the question, it is about knowing precisely what to do and how to do it to get the best result for you and the least chance of a counter or reversal from the other person. It's knowing how to use your strength and speed to negate and overcome the other persons. It's making them uncomfortable and making them burn there energy at a faster rate. It's knowing why something moved a inch one way lets the person escape, and a inch the other way breaks there arm.