What is the difference?

The question that I find to be most important when reading through this section is, do the Britons only feel disdain and anger towards foreign enemies? Geoffrey of Monmouth describes the final battle between Arthur and his army and the Army of Modred. Prior to the battle Arthur gives a pre-battle speech in which he urges his men to devastate the army of Modred since they are foreigners, “mongrels and barbarians from many kingdoms,”(Pg. 86) This motivates Arthur’s army to a victory, although they would suffer heavy casualties in the process. Some of the casualties listed by Monmouth came from foreign kingdoms who had pledged support to Arthur, Kingdoms such as Norway and Denmark. What is the difference between these foreigners fighting along side Arthur and his army and those who fought for Modred? The only plausible difference I can find is that the foreigners fighting alongside of Mordred were fighting to, in Arthur’s words, take the lands and fortunes held by members of Arthur’s army. Were the foreigners in Arthur’s army not fighting for similar reasons? Did they not want lands or fortunes as well?