As we know, the Imperium is a distinctively mediavael and feudal setting in its attitudes and many (though not all) of its cultures. Thats why the concept of planetary nobility is so widespread and why many roles (be they lowly such as Cog Maintainer #58 to the mighty Heir of the Imperial Commander) are hereditary.
Now the Adeptus Astartes are just as mediavael in their own attitudes- especially in terms of honour, personal martial expertise etc. But since they dont seem to have kids, they've escaped the idea of hereditary bloodlines outside of the concept of descent from Primarchs.
Except they dont quite.... They have the genetic seed which transforms a man into a Marine, the progenoid glands which could act as a surrogate descent line.
So, would it be likely to have an Adeptus Astartes chapter who believe that the successor to the Chapter Master, Librarian, Chaplain etc, should be one of the 2 marines who recieved their predeccessors progenoid seed? A hereditary chain of scuccession based not on biological descent, but progenoid implantation? Since apparently the glands can be harvested after 20 years or so without killing the original marine, this also allows the "Father" to train up his "sons" as well.
Thoughts? Any problems with such an Astartes chapter based off this concept rather than individual merit?
SJE