To be fair, Robert The Bruce was a Norman just the same as Edward was Norman. Ironically it wasn't so much about England V Scotland it was a family squabble among the Norman overlords.
Not quite true -the Bruce family had its roots in Normandy - a Robert de Brus had come to England with William the Conqueror's army. However,Robert's mother Marjorie was the Countess of Carrick and descended from an ancient Gaelic bloodline.