That's some mighty poor reporting there - right down to the Star name-checking some internet site for providing the average attendances of the clubs it reports on week-in, week-out. Do they really not know what the average attendances of the local clubs are?
Clubs only pay for the policing within the footprints of their grounds so it's no surprise Wednesday's figure would be higher as they would have the biggest need for policing in the city centre etc with more away fans than United would ever have in League 1.
And if those figures are right, South Yorkshire Police have overcharged United and we're due a small rebate. Police can't charge for services they don't provide but the Star don't seem to have asked what's going on.