Julianos is "the Cyrodilic god of literature, law, history, and contradiction.", and is also known as the God of Wisdom and father of language and mathematics (from TIL). Julianos is also associated with The Elder Scrolls themselves.
Herma-Mora also seems to be master of the domain of wisdom and history ("Past, present, and future are as one to me," he says in Oblivion). In terms of his knowledge, Ted Peterson's interview in TIL says "Hermaeus Mora may mean "A Grove In The Wilderness" or "Hidden Grove," with the suggestion that he represents secret truths not easily found".
So my question is; what's the difference? Who has the greater mastery of history and knowledge? Am I right in thinking that Hermaeus Mora has more to do with 'secret' or 'forbidden' knowledge and the scryings of fate (although The Elder Scrolls also have elements of this, of course), whereas Julianos is more the sphere of 'scholarly' wisdom and studies?