I sure as heck hope this wasn't a placebo change, because I am loving it! My battle groups feel much more responsive, perhaps daring is the right word. I'm seeing most of the beefy units (brutes and Zeus) stepping to the front aggressively going after the objectives. A few seem to be hanging back to guard the artillery units, which seems like a smart idea. I find myself trying to analyze how the group is behaving in various situations.

Once when retreating my squishier units were shielded off by brutes in rear left flank from which the fire was incoming. Medics were within range but out of firing range trying to keep the shieling units alive.

I had a stationary group that was mostly stationed outside of range of targets I saw on radar. One T2 artillery unit edged forward a little to poke at the radar targets, and it was surrounded by medics in case it started to receive damage. I would have liked to see how the group would respond if that artillery unit did start getting attacked. I'd wager actual dollars that it would have retreated inside the relative saftey of nearby beefy units.

Are the above scenarios flukes and I'm giving undo credit to the AI for random behaviors that seem intelligent? Or is it actually that clever and I can rely on that behavior  in the future, allowing me to focus on the overall war? I would love for the devs to reveal in detail how the battle group AI is expected to behave in several scenarios, and perhaps open up the tweakables and maybe even some logic for modding.

I recommend the above change linked by Frogboy be patched in...again assuming I wasn't fooled by placebo.