That's a huge question, lol. But here is one case of the player's party having greater influence over enemy AI than other npc parties would. One of the conditions that makes npcs decide to patrol around a settlement is the so called "alarm state" of the settlement. When an enemy party (including bandits) is near one of the faction's settlements, it will increase the alarm state of the settlement on each hourly tick. The alarm state will raise faster or slower depending on a number of factors. A party's total strength is one of those factors, and the player's party is considered stronger (by at least double) than an equivalent npc party, so enemy npcs with therefore react to the player invading the enemy's land quicker than they would for other hostile npcs. It's really tough to say how drastic of an effect this actually has, but it does make at least
some difference. If there are no hostile parties in the area of a settlement (within 10 distance units), the alarm state will slowly decrease over time. This system causes npcs to prioritize patrolling settlements with a lot of hostile parties in the vicinity.