All games have problems with gunner accuracy. They are either too inaccurate (European Air War), or too accurate (IL2).
The post you referenced was mine. I'm not saying AI is one of the strong points of IL2, it never was. I love this simulator and fly it more than anything else, but the truth is like that. On the bright side of it though, we know enough about gunners in IL2 to avoid getting repeatedly killed in annoying ways.
Heck, even in the new Rise of Flight some people have complained about gunners. They are accurate out to a range of 500 meters or more and that's with rifle-caliber machine guns and unstable biplanes. In contrast, the flyable fighters that the player can use are so unstable that they bob up and down all the time. I don't have that game but people who have it say that you need to get VERY close, less than 100m, to score a good % of hits. Anything above 150m the Spads and Fokkers shake so much that you're lucky if you get 5 hits or so in a 2 second burst. And yet, the gunners can shoot to 500m or so.
I think it's a combination of factors. On one hand, it would consume too much CPU power to calculate G-effects and realistic AI routines for so many gunners, so they use some simplified algorithms that will look more or less ok in the grand scheme of things.
Maintaining a grand scheme of things that agreees with casualty rate reports from real combat is the second reason. Because the algorithms for gunners are simpler than the algorithms for AI pilots, they would be too easy and the player would get too many bomber kills. For example, in European Air War i could kill 18 B17s with my FW190 before running out of ammo and i was attacking from their dead six, they were that bad.
So, the designer has to make sure that killing bombers is not too easy, while saving CPU power for other more important stuff. And that's why in the end the gunners can shoot very accurately and very far, but they can't really follow you through certain attack maneuvers because they are "stupid" due to their simplified algorithms. I have a track of me killing 4 B17s with a FW190A3 in IL2 and they are set to veteran or ace (don't remember which). They didn't even damage my engine. You can do it, as long as you observe the way they function.
It doesn't matter if you come from dead six, from the sides or from the top. Fly in a line
that looks straight to the gunner and he will get you. Fly in a way that might be straight
but looks different from the gunner's point of view and you will survive. They can't really follow you if you do it right, they can shoot very well and very far but only if it looks like you're going straight from where they are sitting.
