I'd agree, most Magna / Parva I've been to were in Leicestershire or Warwickshire. Whilst Great / Little were generally more Northamptonshire / Oxfordshire.
Not so many pairs either, with the Great being missed off e.g. Little Kineton and Kineton or Little Braunston and Braunston
Not so many pairs either, with the Great being missed off e.g. Little Kineton and Kineton or Little Braunston and Braunston