It seems to me to be fairly obvious. All the servants would have been Saxon. Nearly all the lords would have been Norman. These songs would have been popular with the commoners because they show covert resistance to Norman arrogance and intolerance. The servant isn't stupid. The servant is cunning. The lord isn't the noble figure of Christian right he is the oppressor and the all powerful enemy.

It's the lord who is stupid. The servant is a freedom fighter. These are songs of covert resistance.