Why is it always a "fluke" when things go smoothly at T5 and "typical" when they do not?
Because it's so ******* inconsistent - it's not difficult to know how many pax are going to arrive/depart/transit over a given period yet staffing levels do not seem to reflect this.
When it's good it sets an expectation for the future - when it's bad it undoes all the previous 'good' work