When my husband was a policeman and helped to police football matches, he noted that when the football ‘fans’ weren’t getting into fights with away fans, they would fight fans from other housing estates!
As regards the Scots and the English, I remember, many years back in my first teaching job in the south of England, teaching children whose fathers were in a Scottish regiment, next to 2 Scottish teachers, plus a visiting Scottish speech therapist. I seemed to be in a minority group speaking with an English accent!
What is being English? I know in more recent history that my great grandfather was from the Austrian/German border area. Just before WW1. That’s another story! My daughter tells me my blood group originates from Asia. My son, nephew and niece have married either someone from a different country or second generation here. We are all melting pots of different nationalities. I have no patience with prejudice of any kind.