He has the Paladin holding the books for them.  He gesture to each book.

"This booklet is the standard handbook rules of war the teach all their literate soldiers and have all their soldiers learn at least the basic outline of.  It covers illegal orders, and is fairly short, but it is intended for common soldiers, not high circle wizards or sorcerers who might have a few spell remotely comparable to your potential destructive power." 

The booklet does indeed look short, they could probably get through it in under an hour if Jon reads at a constant pace.

"This book is a set of guidelines and procedures for higher circle casters, including those directly part of the army, and those on some form of contract as mercenaries, adventurers, or hired on a per-spell-basis.  Lastwall doesn't want anyone working for them to have to risk their alignment and their procedures are definitely adequate to avoid an Evil alignment in the course of working for them.  The chapters on large scale destructive magic are at somewhat relevant to your capabilities, enough to potentially be a useful guide on what policy you would need to avoid counting as Evil."

The book is thicker, but they could probably get through a chapter within an hour.

"This book is a much denser treatise, covering many case studies, Commune results, consultation with Outsiders, moral reasoning, analyses of magic, and theological reasoning, all aimed at a definitive study on ethical uses of magic in warfare.  The author is often hesitant to pronounce definitely correct policy and instead usually frames things in terms of tradeoffs in moral and systemic alignment versus achieving military goals.  As you can see, it is a much longer read, but I might be able to find some subsection relevant to you to start with?"

The last book is very thick and hefty.

"What about guidance for field commanders and operations planners? At the risk of repeating myself, magic is not the most destructive force available to the Germanian army, and my or any one mage's personal abilities are rarely decisive in an encounter and never in an actual battle. ...arguably excepting the times I used the cursed orb, but I never achieved a power output combined to an actual artillery barrage. And I'm - not used to thinking of the rules of warfare as being different for mages, although that might be because my second Earth has not had aerial mages for long enough to develop such rules."

"As a mage, but I started out as an aerial artillery spotter. Later I commanded a battalion of forty-eight aerial mages each with an orb as powerful as my own, which I helped form and train, and my decisions while in command surely had more affect on every conceivable outcome than my personal use of magic. By the time of my abduction I commanded a combined-forces unit of upwards of a thousand men, including infantry and tanks."

"Normally I would of course start by learning the rules for common soldiers before considering the officers who must command them, but we are pressed for time and I'm not sure the second step after that should be something specific to local mages working with tools very different from the ones I have."

"Lastwall has books written specifically for field commanders, sorry I did not realize I should get one.  I could leave to go get one if you would guess that is the area where your procedures most likely differed from Lawful Neutral or Lawful Good procedures?  The book on guidelines and procedures for high circle casters does covering operating as a commander of them, but it isn't its primary focus."