Calling all armchair generals! Boudica's Last Stand.

[Renatus]

That's the trouble with dodgy translations; they can lead you astray.  Tacitus is perfectly clear.  Suetonius chose a position in a narrow defile (artis faucibus), making sure that there was a forest behind him, so that he could not be attacked from the rear, and an open plain in front with nowhere for the enemy to hide and spring an ambush when he emerged from the defile.  After the pre-battle speeches, he maintained that position, using the narrowness of the location as a protection, i.e., so that he could not be outflanked, and awaited the enemy's charge.  When it came, it was smashed by a concentrated barrage of pila and the Romans launched their counter-attack.  The demoralised Britons turned tail and ran and the slaughter began, any pockets of resistance being ridden down.  The Britons could not simply flee the battlefield because of the physical obstruction of the wagons and the draught animals but also, as has been pointed out elsewhere in this thread, although not specifically mentioned by Tacitus, because they would naturally try to rescue their individual families and would dash about trying to find them, obstructing each other and adding to the chaos.  Dio's description is of a more stereotypical battle but may contain a kernel of truth in that it was probably not as easy as Tacitus makes it appear.  Nevertheless, the resulting bloodbath was the same.