Not entirely true, the only person who truly knows everything is Grand Master Azrael, next up to knowing the full truth is Ezekiel (as he is the keeper of keys and head librarian) or Master Sapphon (as he is the leader of the chaplains) At this point some DA fans must be WTF? Who is this Sapphon guy who should be Asmodai?!?! Yes he is the "Reclusiarch" of the Dark Angels, Asmodai is older and more capable, but Asmodai for lack of a better word is an asshole. Sapphon leads out of inspiration. Asmodai leads through an iron fist and fear. (Yes fear... even to the astartes who feel no emotion.) Belial and Sammael are abouts on the same page, but being captain of 1st company will earn you more knowledge on the situation which puts Belial a smidge ahead of Sammael. After these 2 Iconic Dark Angels, the captains are ranked in order of the company number, then falls back to the Deathwing Knights > Deathwing and then the Ravenwing Black Knights > Ravenwing to the members of the Inner Circle, then finally your regular marines and then onto the scouts who know more or less... nothing. If you want a good insight to the rankings of the inner-circle read "Ravenwing" by Gav Thorpe. The book is amazing and the end gives you a good insight to the inner circles workings.