I get the sense the main text is written differently than the first volume. There's no handy key at the start of the book telling you what is impartial and what is not, and the tone of the author seems less detached an encyclopedic. It's appears written much further in universe, with certain biases and opinions of the author occasionally shining through.
For instance, it sometimes refers to the Maker and Andraste as "our Maker" and "Our Lady." It also appears to advance a certain thesis when it comes to certain topics. In that way it reminds me a lot of when different scholars who do research into biblical history they can often come away with very different conclusions.
For example, on the topic of Maferath, the first volume simply stated that according different versions Maferath might have been motivated by jealousy or by practical concern they could not win the war.
In this volume, there's a paragraph talking about the importance of "we" [historians] needing to be apologists for the harsh truth that make them unwelcome in halls of worship. And it talks about the differences between how the faithful remember Andraste's Exalted March and how history remembers it. Basically, it seems to imply that Mafterath did the right thing. It also paints Andraste as the ultimate idealist that was sort of blind to practical concerns. Funnily enough, there's a brief line in The Masked Empire where Celene considers the works on Andraste's life that suggests the opposite: that Andraste was actually a lot more pragmatic than the Chantry might like to remember her.
I suppose it's hard to tell sometimes given that our characters have dramatic adventures that are true in the games but, I remember feeling like the section on the first Archon Darinius sounded like it was repeating a possibly embellished Tevinter legend rather than a historical account because it's filled with things that would make a good story. Such as the future Archon being smuggled away as a baby left in a basket while his treacherous uncle murdered his mother, then the subsequent hero's journey rising through the ranks of the Priesthood of Dumat, ignorant of his royal heritage, to avenging his mother and becoming ruler of the neromenian kingdoms. Also forging relations with the dwarves by personally taking part in the proving and singlehandedly defeating many champions before impressing the Dwarven King himself by fighting him for several hours.
I don't know if this is a theme of the book, or a coincidence or the actual direction Bioware wants to take now, but I kind of get the sense elves are almost specifically forgotten or left out.
The section on Archon Thalasian destroying Arlathan seems to retcon thousands of years of history between elves and humans because it says the Imperium was unaware of the existence of elves before they destroyed Aralthan. It also contradicts what Abelas said on the subject, which is not surprising since the page on Abelas immediately dismisses him as a deluded leader of an elven sect that somehow convinced himself that he was immortal. And it suggests this is surely the case based on the fact that "he talked about Mythal as if she were a living god and not a story."
The section on the source criticism of the Chant of Light also suggests that Shartan might not actually have existed at all, and may have just been an ideal from the various elven slave rebellions. Even though we know from the game that the Temple of Sacred Ashes has an actual memory of him (or I assume that's what those ghostly visions were.)
Part of the section on Kordillus Drakon bafflingly almost seems to forget the Dales existed at all, because it says he conquered well into modern day Ferelden and helped stamp out remnants of the Cult of the Old Gods and various Alamarri beliefs there. But how could he have done this if an elven Kingdom was in between the Orlesian Heartland and the Ferelden Valley? Did he he his armies to conquer completely around it?