We'd have to think of it as several projects, I think.
Let's walk through a historic figure as an example.
A knight (honor) might have been a professional soldier (occupation) for different armies (? How categorized?) in different conflicts (wars, battles). He might have started as cavalry (unit) officer (rank) and ended his career as a lord High commander (? Government official ?).
Generic
- soldiers
- sailors
- ??
Might be best.
For a knight it will depend on the period. Knighthood was not originally an honor, but later became one. There was a period when every man of a certain class became a knight upon reaching adulthood. People could pay to be excused from that military obligation, and still later it became routine to excuse everyone unless they sought it.
By definition, a knight / soldier was always cavalry. Not so after it became purely an honor. Similarly, in the original form of knighthood a knight was generally a type of officer in the sense that would command a sergeant or two and some pikemen and maybe archers at his own expense from his own manors.
I think it would be a mistake to try correlating knights to later military organization.