This is the damning indictment of Bruce's "tactics": he is incapable of making any adjustments to the teams approach, even at halftime.
He's a cut and paste manager and then he looks clueless as his tactical approach is slowly dissected and then shredded. When a team figures how you are playing and then counter it, you have to be prepared to counter their changes. This isn't the dinosaur days when everyone plays the same and the difference is team motivation and individual play within the same tactical construct.