I think the Prof. has it right, by waiting for them to gather you create a them and us. The police should have been scattered throughout the road asking people to move on in a none confrontational way, maybe even a van slowly driving up and down to force people to move. "Busses that way lads. Pubs in Digbeth are open, its only £2.80 pint" rather than "move or we will kosh you".
You tend to find that if you treat fans like animals you get the reaction you appear to seek.
Bladen does a good job as he's affable and approachable and comes across as a normal bloke even if he is in fancy dress. I can understand Sgt Wilkinson being a bit miffed as he's suffered two bumps to the head, but if your preconceived notion is the Noses are animals then its not helpful.
He knows full well that what he was facing wasn't their firm and that there wasn't a single Category C individual among them, so the real "animals" were drinking elsewhere. Just kids in bad designer clothes that ought to have been handled differently to disperse.