to put it in another POV, giroud and theo combined is a complete striker.
giroud is the one touch magician who can finish and assist with his one touch passing/shooting, he can head the ball, hold up play, link up play and provide physical aggression to put pressure on defenders. but when he has the ball he rarely runs past players a la wilshere to create chances on his own, or run onto through passes.
theo is the runner who runs onto through balls and plays at the edge of the opponent's defence line. last season he was scoring, this season he hasn't. they both complement each other.