@ Balto
I am addicted to il-2 since 2006, mainly I am offline player. From 4.08 I have tried almost all mod packs starting with AAA 1.1, stock campaigns have never been enough for me so I have always created my missions and campaigns, until today. And I can tell you that AI behavior has never been perfect and never will be but practically always problems are caused by poor mission design and bad expectations (lack of knowledge and experience).To really enjoy Il-2 you have to know it, knowing the history isn't enough - it is a big (and common) mistake to try to apply reality to the letter in missions without take into account the reality and capacity of the game. If you are going to fly thinking about real aircraft performance you will only get frustration because FMs (especially AI) don't correspond 100% to historical reality, you have to fly (and create missions) according to what our sim offers you...
Many times it has happened to me to leave a mission because it was impossible to get desired AI behavior, but when I took it back a few months later I found a quick way make it run smoothly with a little more knowledge of the game.
the kind of mission you need weeks to tune
...if so i think you try to create not a mission but a show with a very concrete and rigid scenario where result is known before starting, why play a thing like that?
If you want to make exact recreations of history instead of Il-2 use Blender, it would be better...