People are greatly overstating the degree to which England, Scotland, Wales and N. Ireland are separate countries. They are for some purposes, but not for others. They are each member states of FIFA, but in the UN are members collectively as the United Kingdom. The same is true in the Olympic Games, where the four participate as Great Britain. You may recall the controversy around the 2012 Olympics in which England wanted to field a Great Britain team, but the associations in Wales, Scotland and N. Ireland all protested, fearing it would threaten their standing with FIFA. They actually threatened retribution against players who agreed to play for the unified team.