Where were their armies?

At the start of the film, a truce meeting is being held between the Saxons, Britons (which included what we today call Cornish, Welsh and Scottish), Angles and Jutes etc to unite against the Irish raiders - not that they would unite in history, but never mind, it's Germanic fantasy.

We hear the alarm- the Irish are attacking, and the meeting's nobles draws arms... but we don't see or hear of any of the confederated armies' soldiers, who would most likely have been so large combined that they would be camping outside the great hall? Or even outside of the walls and faced the Irish first?