When a Unit has no parent the comment of the superiorUnit field says that the superiorUnit may be empty.
But what is meant with that (all 15 bytes bytes zero, not updated at all, etc.).
Maybe it is better to make the superiorUnit uuid equal to the force uuid (top of the hierarchy) when there is no parent. A unit always belongs to a force and then there is no problem with the structure of the field since they are the same.
When a Unit has no parent the comment of the superiorUnit field says that the superiorUnit may be empty. But what is meant with that (all 15 bytes bytes zero, not updated at all, etc.). Maybe it is better to make the superiorUnit uuid equal to the force uuid (top of the hierarchy) when there is no parent. A unit always belongs to a force and then there is no problem with the structure of the field since they are the same.