These are distinct from the lands of Ballumbie, which were last in the possession of Robert Williamson of Ballumbie, hence there is a Laird of Ballumbie Castle as well as a Laird of Ballumbie.
These lands differ from Ballumbie territories, which were previously owned by Robert Williamson of Ballumbie. Thus, there is a Laird of Ballumbie Castle alongside a Laird of Ballumbie.