They played for the UK team in an earlier Nations Cup, that's why they added the UK flag as wellIts a running joke because Mattheus (Melkor) and Timotheus (Feanor) live in ireland but have a dual citizenship so they played for USA in nations cup. I think the UK flag is added just for fun. I believe the dual nationality part is correct but not 100% sure.
i still think thats what it isI always thought that was three guys playing at the same pc like some kind of megazord