This kind of arrangement is an anachronistic historical model which was developed between the sixteenth- and twentieth-centuries. For more information see this FAQ post and please consider re-posting this question to the forthcoming AMA: 'Feudalism didn't exist: the medieval social and political world'.

In short, at the 'height' of medieval feudalism (the High Middle Ages) the social and titular structure of Europe was much more fluid than the archetypal 'feudal pyramid' allows for. For more information see David Crouch's The Image of Aristocracy in Britain, (Cambridge, 1992) for the development of titular aristocracy in the oft-cited 'feudal' post-Conquest society; and The Birth of Nobility: Constructing Aristocracy in England and France, 900-1300 (Harlow, 2005) for an explication of the development of feudal historiography.