Yes, that's a clear distinction between the two groups. Well spotted! The Cult of the Unwritten Book is totalist (although I suppose that they would speciously argue against that with a malaprop use of the word 'totalist' by saying that they are against Totality in favour of Nullity), they have a rigid heirarchy (the Archons) and, most importantly, they lie to you when you come in the door. They certainly lied to Elliot the Book (love the lines "We don't kill kids!", "Or burn books...well, he's both.") and, in the comics, the straight-razor wielding nuns are tricked into the transformation into said creatures.

The Cult of the Rewritten book might bear a charge of Totalism but fail on the other two counts. That they're not rigidly hierarchical is shown by their staff meeting. The objection that "I too question the use of the male pronoun in this exercise." when the consensus is moving towards a dog messiah would get you excommunicated in a second in an abusive cult. And of course, they're totally up front about being all about a giant eye-in-the-sky that will engage the decreator in a staring contest.