AIW1 has a couple of mechanics around how the AI reacts to differing levels of human ships on its planets. I'm not sure how many of these, if any, are coming back:
* If you bring a small force into the system, defending ships won't wake up until you get close. If you bring a larger force, all defenders in the system will wake up and go into threat behavior.
* AI Eyes won't wake up unless you outnumber the AI forces in the system by a certain amount. If you bring few enough ships they won't wake up regardless.
* Carriers deploy their contained ships to maintain a certain target number of ships in the air based on the local human presence.
If these do come back, I think it would be helpful to have a visual indicator of the thresholds. I am imagining a bar across the top of the screen as part of the HUD that represents the local 'AI Alertness'. The more human ships you have in a system, the higher the bar. Then, you could draw various thresholds onto the bar: this many ships will wake up defenders, this many ships will wake up the local AI Eye, etc.
Then, if you have a bunch of ships selected in one system and view an AI controlled system, you can add an indicator to the bar that says how much alertness there will be once those ships arrive. That way you don't accidentally bring in too much and wake up the defenders or trigger an Eye; you know exactly how much you can raid with.
This would also make the mechanic clear enough that you could have units specifically interact with it; raider-type ships could be discounted in these calculations.
