It has grounding in the Roman Republic's manipular, or Polybian, legion. You can see the police forming blocks, which would be similar to Ancient Roman maniples I suppose, and you can see the maniples maneuver between each other much like the maniples of a legion in the triplex acies would. The spreading out of the police is not something the Romans would do, regularly at least. Roman legionaries would remain shoulder-to-shoulder with their shields, their scutum, held like that. And the soldiers most certainly would not be running around through the ranks like the police do.

But the foundation is there.