So, I just encountered a problem regarding the AI for ranged units.
If you have ranged units, like the Artemis, ultimately, you would want them to stay out of range of enemy units and defenses. Unfortunately, the AI constantly has your Artemis close into the range of the enemy, even if you have sight / radar range on them. This creates a situation where you must constantly micro said units. It also creates problems since you have to shuffle your Artemis back, creating a situation where they can't shoot (since they only shoot forward).
I also noticed something similar for scout aircraft. Scout aircraft shouldn't move into range and attack units unless they are ordered to. Otherwise, they may move into range of enemy anti-air and get killed off easily, thus defeating their purpose.
I see a solution either being to change the AI or, better yet, create "stances" as you have in similar games (like Dawn of War, for instance). The AI behavior will change depending on the stance they are in.