Of course the AI is scripted to stick to a run rate and clear the boundaries at will.
I cannot truely fault them at that, because in reality the bowlers make mistakes and get hit. Good balls are defended. And some good balls are hit. So there is a balancing factor.
Now in the game, the balancing factor is messed up, because with some practice and muscle memory anybody can bowl 6 good balls. No matter how small you make the window. This problem is common to many games.
In DBC 14 & 17 , AI were simply unable to post good scores. We could get 5-6 boundary catches every match. And the matches were unplayable that way.
So I guess, this time BA went the other way, so that at least we can get a good match.
Now, BA need to find a way to tackle the Original problem by adding more factors to the fray for Human Bowling and/or optimize the AI batting further.
I feel, the current build ODI rates could be suitable for T20. But they need to up the randomization a bit more too. Because otherwise there is a clear pattern.