Well I am pretty new, and I experienced something for the first time.
I was assaulting an enemy town, I had hit the edge with artillery, smoke, and had an active AH64 CAS mission on the area as well. One of my infantry units was moving quick to a building. Just inside the perimeter of the AH64 attack area. It hit them with cannon fire! Killed 2 and wounded 2, it was shocking to be honest, I paused the game. Kind of wish I took a screen shot.
There were no enemy units around, they were still 20m at least from the closest building in a field. This game amazes me every day.