I don't know if it's something being done in the beta, or even if it's a useful suggestion someone would like to take on board. But I think taking field maps of where people are hitting and comparing with the fields that are used (they must be able to identify those that are used in the 41-50 over period) could at least give an idea of how a field needs to be adjusted, new fields need to be added or changes made into the lines and lengths that bowlers use.
I don't think you can work on enhancing batting or AI in a cricket video game without factoring in the AI fields as they go hand in hand. Both the AI and the batting (shots and their placement) are complementary to the default AI fields. As an example let's say Big Ant fine tune the batting and enhance back foot shots along with fixing the issue of some shots not going as intended (e.g., backfoot lofted cut shot going towards Extra Cover instead of 3rd man region). And say they also enhance the AI in terms of bowling proper line & length (in the channel outside off most of the times) and minimizing extras & freebies. This would all come down to zilch if the default AI has fields with 3 slips with no fielder deep in the cover region or nobody deep behind square on the leg as you can get easy boundaries despite enhanced batting and AI resulting in the same frustrating experience.
That's why IMO Big Ant has to first look at the AI fields. That has to be the starting point. Focus on some core group of default AI fields for shorter formats and Tests for pacers and spinners. As an example if I've to pick a field for a odi (or T20) with 5 fielders out I would have Deep Fine Leg, 3rd man, Deep Cover, Long on and Long Off as my default field. Now if I intend to bowl short of length delivery, I might bring in Long Off in to mid off and have a Deep Mid Wkt (or Deep Square Leg). Similarly if my strategy is to bowl fuller (yorkers) outside off, I might bring in Fine Leg to short fine Leg position and have a Deep Point to complement 3rd man and Deep Cover. I mean that's how Big Ant needs to think about AI fields and the AI strategy in general. They go hand in hand coz if you simply look at posting your fielders out at random, it won't help anything and you will end up with a frustrating experience of having AI fields with Deep Mid Wkt, Long On, Long Off, Deep Extra Cover and Deep Point, and end up conceding easy boundaries to fine leg or 3rd man regions.
Another aspect is some sort of situational awareness. As an example, in an odi if the asking rate is 6+ then don't have a field with 3 slips. Put pressure on the batsman by having the max fielders out and forcing them to make a mistake. To make things simple, I would recommend Big ANt go with fields with max fielders outside the fielding circle no matter what the situation in shorter formats. Similarly in Tests the AI has to understand when to attack and when to be defensive but I'm not sure this logic can be patched in. It's way too complicated to be patched in a few days and is part of core gameplay.
Cricket is all about strategy and planning on how to set up & eventually dismiss a batsman, or how to limit the flow of runs in shorter formats. This cannot be done without AI, batting (shots which are consistent across both front & back foot) and AI fields in sync with each other. Even if you miss out on one aspect of the gameplay, you will end up with an unbalanced gameplay resulting in similar frustrating gameplay experience which we are currently facing.