Because the SCLs are violating their noncombatant status by directly hitting AIP
I could go either way on chiv+SCLs, but it seems like it would make the game rather easy indeed to just liberate all the SCLs and ignore them forthwith.
That's reasonable, but if that's the case the description needs to be altered. Right now it says it won't do what it actually does, and as tmm mentioned it's not very chivalrous to attack civilians.
Maybe change it to something like "won't attack irreplaceable production or power generation facilities." Something that makes it clear that it's not going to ignore everything? (Or leave it as is, since it is an easy AI, and the second AI player could theoretically still attack them.)
On the champ response hitting you with 7 champs at once when you only had a 1-nebula frigate, I'm not sure why it would be that big that early. What was the clock at?
That was at 2:46. I was about to start a second nebula. Considering how long the nebulas take, if I'm going to get that crazy a response to having one frigate I'm probably just going to turn it back off. It's a fun unit, but it takes a lot of attention and really isn't strong enough to justify that crazy a response. (That was the same Chivalric AI mentioned above, maybe it's getting a bonus by mistake or something?)
edit - Started up a fallen spire normal + champion game with the same two AIs. I'm seeing an inordinate number of AI shadow frigates again, and once again from the Chivalric AI. I'm not sure if that's a coincidence, or if that AI is just getting a really high number of shadow frigates (maybe due to it's CPA bonus?). Now I wish I'd turned off fog of war so I could see if it's really just that AI or not.
On another note - in another game I had the bouncer AI, a planet early on that I needed to capture for Fallen Spire (the first remote shard), a Raid Eye on the planet, and an interplanetary munitions booster. That was...
interesting.