Isn't that pretty much the indirect definition of football intelligence? Playing mature (=smart) and being productive/effective without having to rely on flashy stuff?
That's not what makes Müller special though. The intelligence in his movement without the ball isn't simply described by workrate and being productive at the end of an attack. His runs without the ball are incredible clever and very often create dangerous situations for other players. He's heavily involved in the attack even when he's not touching the ball and not just a few times, he's doing that consistently throughout the game.