Tactical command? Who exactly do you think Boudicca was leading? They were not a professional organised army, but groups of warriors led by chieftans and respected warriors. Tactical command in these cases is very limited, and in any case, I doubt the britons were much into tactics anyway. Too complicated. There's the enemy. Let's attack them now!
To follow-on from Caldrail's comments what you have to realise is that in the period the 'British' army was not a unified fighting force. It was in all likeliehood composed of a large number of individual 'tribal' groups each under the personal command of their own leaders and with disperate equipment.
The best that Boudicca could have hoped for in such a large scale battle as finally occurred would be to get them all more or less lined up in one place and hopefully agreeable to attacking when 'asked'.
Any 'tactical' command would have been down to individual leaders deciding where and when to send their own force and in the event when to try and run.