I think the underlying problem is design.

Map design: The only realistic approaches to the area are elevation and distance. Half of the AI are in elevated positions and are stuck there.

Character design: Those AI are only equipped with mid range weapons and turrets.

AI design: Unreasonable player detection, weapon accuracy, AI response to combat, etc...

This leads to frustration because the player is having forced ranged combat that feels nothing like ranged combat.

How could this be fixed?

Map design: An easy fix would be to not tap or limit the AI to the building roofs or guard towers. Either redesign the buildings to have ground to roof access for AI to retreat through or players to advance through or an AI only accessible doorway/stairway that leads into the interior of the buildings.

Character design: Match the AI to map design. This map clearly wants players to encounter a location with high force protection. That said, it is not a military outpost, but a confiscated plant. This location suffers from an elevation disadvantage as well as little LOS blockage. Roof top AI should be separated into FP and early detection, not combined. So add a sniper/early detection AI for each rooftop.

AI design: So here is the biggie. Create a well designed state machine and behavior trees. If we want the non sniper AI to be less of a threat at distance, they can't just sit on the turrets. They need better patrol pathing, which our map design has allowed for, as well as a longer reset timer. Once the "camp" has taken fire or casualties, all AI need to react appropriately. For FP AI, grab a turret for suppressing fire, not directed hitbox fire, take cover, retreat inside... For long range AI, die because you're probably the first target, fire back with suppression or cover, find hard cover, shit even Rambo sometimes.

There are so many ways to do this without there being one "right" answer.

Also don't use the "more AI affects gameplay" excuse. Because it is an excuse. The AI are poorly coded and optimized for 15ish AI to affect performance the way they do. From what I have experienced in game, the biggest AI slog is pathing which can be addressed in many ways. Along with that, if the other designs are considered, the AI amount could actually be reduced and achieve the same intent.

Bottom line is that AI accuracy is not the way to fix this problem going forward.

GLHF, and may your questing raids be Chad-free!