It is subtitled "Trust in the Gods but Verify" and that reminded me of this friend saying "trusting is good, verifying is better". It's a compilation of articles, chronologically arrayed from the Early Republic to Diocletian. It is a pleasant read and it points to reflections in many directions.
The following passage immediately made me think about skill-equipped games and when to enhance those skills.
Where did Roman generals learn the craft of intelligence? When appointed to command an army, a commander would have to acquire the pertinent skills himself from textbooks or from the harder lessons of personal experience. Cicero recounts the classic example of how Lucius Lucullus devoted his early years to legal studies and a quaestorship in which he saw no military action, and was then posted off to the Mithridatic Wars. He spent the entire voyage partly in acquiring advice from experienced men, partly in reading the achievements of others, and arrived in Asia "a made general," although he had been ignorant of military affairs when he left Rome.
A parenthese here, do you remember of the pleasure of walking and having a conversation with friends as the road unfolds?
In a game, it might be ok to allow players to let their characters teach each other. But I'd prevent characters with low wisdom from acquiring anything easily, they should be certain they know the "right way" (and some of them might be loud about it).
(How about a funnel where level 0 characters have their humility gauge at 0?)
One skill that should propagate in the party is "Heal" or its equivalents. And if a character, as played, is too stupid to learn "Heal", they are not exempted from helping carrying fallen comrades.
Camp, forage, hunt, heal skills should perhaps be perfectible on the go, not through the gate of advancement, and having mentors should help.
Could characters learn to read or learn languages on the go? Could they learn advanced subjects while the landscape slowly changes?
Young commander apprentices are "promenaded" by their teachers, and when coming to a place they are given time to gather information and then they have to detail the location and how it binds into the net of more or less adjacent locations. And then the question falls on the young person: "how would you go about taking this place?" or "how about defending it?".
Where did Roman generals learn the craft of intelligence?
I am not an historian, but as a game referee, I have to make up, scaffold, worlds and I'd say that aristocrats in such societies are born with access to "factional" intelligence networks, and that, probably, the intelligence craft at general level requires them to step up from their native network.
They probably travel with their entourage and that team is gathering information and intelligence all the time. Jeeves has Bertie's back.