Seriously though, the old bill were there because (some) Millwall and small heath fans have a reputation for violence. If there had been no Police do you think there would have been no trouble? It would have been a riot. Reports of blues fans throwing coins at the police horses.
Makes me laugh that some clubs romanticise their 'firm' and look back with dewy eyed nostalgia when you could go to a game and kick someone in the head or glass someone for supporting a different. team.