The presence of a soothsayer might remind readers of another Roman play of Shakespeare’s –
Julius Caesar, in which a soothsayer famously tells Caesar to “beware the ides of March.” While the common people once feared they would be devoured by war or by the patricians, they’re now emboldened and empowered, and so threaten to devour Coriolanus (still called Martius by Menenius, because news of his renaming hasn’t reached Rome yet). The tribunes continue suggesting that Martius is prideful as opposed to a genuine Roman hero. Menenius is known as a friend to the common people, but he realizes the way the tribunes have harnessed the power of the common people for political gain.