User blog comment:Pualover/Overlord Power Level/@comment-1846146-20151004122301/@comment-25356962-20151004124047

Actually, the 8 hierarchy was stated by author, and it does mean the full power of nazarick, so maybe they counted as one. And for tabula being stronger than ainz, it's not entirely true. He is stronger in pure destructive magic, but in overall magic maybe momonga stronger than him, reminder that actually momonga placed as mediocre in middle tier for destructive power, but in reality placed as above mediocre in upper tier because of his equipment and skill. And momonga placed in 5th place for being the strongest in the guild (after 8 hierarchy, rubedo, touch me, ulbert)