The player has that tradeoff through events, I was referring to ambitions - each ambition grants you legitimacy, and this is what the AI pretends to have.
As long as the AI has “completed” fewer than 10 Ambitions, there’s a 1/15 chance per turn that the AI will “complete” one. In that case the ambition will be a normal one with a 2/3 chance or legacy with 1/3 chance. The ambitions that the AI “completes” this way grant the legitimacy/cognomen benefits but don’t count towards a victory.
Even if the AI doesn’t actually get events, there’s a system in place to pretend they do, occasionally granting them a bonus from an event. There’s a 1/3 chance per turn for an AI player to randomly get a bonus associated with an event. These bonuses are a small subset of the bonuses you can get from events, so specific bonuses that have been “approved” for the AI. They are: one for an “average” gain of each resource (our system has gains/losses like “average”, “tiny”, “large”), +1 bonuses to the leader’s rating, joining courtiers, a free unit. These bonuses are in turn weighed so that courtiers and +1 to ratings are more common.
The two major things that these pretend events accomplish is to give the AI courtiers (events are the only way to get them aside from a bonus card), and to provide them with at least part of the bonuses you’re getting from events.
I actually think we may need to take another look at all that because the AI tends to fall behind on legitimacy quite a bit, it never gets event legitimacy. To illustrate, from a game I’m playing now, my legitimacy. I have 268, of which 68 came from events.
Here’s the legitimacy of Assyria, the top scoring AI:
Considerably lower as you can see, and Assyria has 39 orders per turn to my 56 orders per turn. The +19 from Events showing up for Assyria there is the family seat bonuses (+15 always), a few Wonders, and a few -1 losses from missions.