We can’t have @warzan have all the fun with this, can’t we ? 😉
I think it is a very interesting idea to have some sort of generic ‘AI’ that could apply to multiple systems.
It’s not going to replace a real opponent, but it can be good enough to teach beginners something about tactics and strategy the moment they decide to do something other than a ‘kill everyone’ scenario.

One probably would have to tweak the exact execution of each posture a bit based on amount of objectives and their location.

If there’s 3 objectives (A, B and C) then it makes sense for part of the army to focus on whatever objective is closest to their location.
And as you’ve mentioned in the show … strict adherence to posture can be very boring from a gameplay point of view.

Besides … even historically speaking not every commander made decisions that were 100% logical in the circumstances.
Although the historic commanders don’t have the detailed info on enemy troops (and even their own troops) like we do in games.

OTOH … an ‘AI’ based enemy may require a less traditional army list that allows for ‘surprises’ (multiple waves of reinforcements)

The game ‘Anno Domini 1666’ may have solo rules, which the team mentions is done by giving the enemy a very basic set of skills to use as ‘complex’ ones would require too much decision making that could slow down the game.
I suspect same may be true for a generic ‘AI’ for wargames. Some aspects simply are too complex to manage without the aid of a computer … and ideally things should be kept as simple as possible.

https://www.kickstarter.com/projects/1263001724/swords-of-light-and-darkness/posts/3182592

I know Fallout was mentioned, but I don’t know enough details for a link.
Likewise the ‘mini flow charts’ that apparently were used for a few units in 40k elude me at the moment.

I reckon the generic ‘AI’ would need both a system of defining the effect the postures have on the various orders that troops can execute as well as some sort of ‘sub routine’ that allows units to execute an order to the best of their ability

Special units and their unique abilities (like artillery and air support) may have to be ignored for the sake of simplicity.