No, three is just an arbitrary number for their example. The point is not the exact number of roles but the fact that the basic legal unit is the relationship, not the person. For instance a prince-bishop might in principle be subject to an archbishop as a bishop, subject to the Emperor as an imperial prince, subject to the King of Bohemia (who was in turn subject to the Emperor) as the holder of a secular fief, and part of the Polish nobility, all at once.
yes this is true today - some researchers have identified the LEGAL definition of a person taking over from the biological definition of a person, in modern times. If you consider the realms of finance, things are definitely not consistent nor fully resolved.
Yeah, in retrospect I realized the three might be distracting but it was just the example I thought of at the moment. (It gets even worse if the guy also has burgher status in a free city!)
