Calling all armchair generals! Boudica's Last Stand.

[Renatus]

So, I hope you will agree, that if you were a rich person from north of the Thames, deciding to take all your valuables over the bridge and head toward Gaul (and Roman-friendly areas of the SE), that you would put whatever pressure you can, to hold or destroy that bridge so that there are no hoards of Iceni flooding over, and so that you can escape.

I will allow you this, it is by no means impossible that someone who had decided not to leave London with Suetonius might have had a change of heart and considered that they might be safer south of the river.  Indeed, there might have been several such persons.  Nevertheless, this is unlikely to have applied to everyone and there will still have been those who stayed put for the reasons enumerated by Alan and stated by Tacitus.  If your rich person had sufficient influence, they might have engineered the destruction of the bridge, leaving those remaining north of the river at the mercy of the rebels.  This, of course, is entirely irrelevant to the movements and actions of Suetonius.

We also see that whether it is at the time, or becomes as a result of this campaign, the use of defensive barriers such as Hadrian's wall and the Antonine wall become the way that the military fight in Britain. The Thames-Berkshire downs is clearly such a line of defence and as such is clearly the original line that gives rise to the other Roman walls in Britain.

Hadrian's Wall and the Antonine Wall are products of the 2nd century.  Hadrian's Wall was erected 60 years after Boudica's revolt and the Antonine Wall 20 years after that.  They reflect the thinking of their time and have nothing to do with the AD60s.  Hadrian's Wall was the brainchild of an emperor who considered the Empire to have reached its limits and did not intend to expand it further.  The Historia Augusta states that it was constructed to separate the Romans from the barbarians and it thus demarked the boundary of the province.  Breeze and Dodson and others have argued that it served to regulate traffic into and out of the province.  In so far as it had a defensive purpose, it was to provide a series of bases from which troops, upon the prospect of a threat from the north, could sally forth to confront the enemy in the field.  It was not a defensive structure to hide behind.  The same applies to the shorter-lived Antonine Wall.

So, whatever all your books say about "the way Romans fought this or that way", the simple fact as shown by not one, but two, or even more lines of defence, is that the Roman practice at the time was based on using lines of defence. YOU CANNOT DENY IT. So, to put it rather bluntly your books are a load of codswallop flying in the face of the clear and obvious evidence of defensive lines in Britain.

I can deny it and I do.  All we have for the period we are discussing is your unsubstantiated theorizing.  To dismiss the findings of scholars who have researched these matters and have the sources to support them as codswallop is just plain arrogance and, frankly, not worthy of further discussion.