If Champions are going to provoke an additional, offensive AI reaction, will the other AI reactions be toned down? The additional wave size modifier, the nemesis spawns, etc.
Personally, I still think that on difficulties above 9, the Champions are more of a hinderance than a help in the long term. The Threatfleet and Special Forces can permanently shut down your Champion if they get big enough. With the enhanced Homeworld defenses now available to the AI, even the Champions and Nebula Ships do not provide any great advantage in that fight, either.
Of course, I've been trying for months to beat a Diff10 Heroic AI when I'm using Champions. I'm beginning to come to the conclusion that it's not possible, no matter how I cheese. And I long ago gave up on multi-Champion Fallen Spire at higher difficulties. Just... no.
Thinking back, I thought that one major point for creating the Champions in the first place was to give a player something to do to prevent boredom during the downtime. "Fleetwipe? Time to whip out the Champion and go do a Nebula while I rebuild." If you can't use your Champion during reconstruction or downtime, it sorta ruins that idea...
I think any anti-Champion plan should be limited to impacting the Champion. Yes, an EMP attack or a instant double wave triggered by the Champions is an effective way to punish the player for using the Champion. But it punishes the use of the Champion by impaction something ELSE. No direct cause/effect. Champion wins a nebula, Anti-Champion units blow up your fleet. Wait, what? That's just not fun, to me. But something like Champion wins a Nebula, Anti-Champion uses a Shadow-virus missile to temporarily knock the Champion down a hull size. That make sense, is logically connected, and just plain more interesting.
The one component of the game designed for Champions, the nebulas, are currently well balanced for them. With 1 Champion or 8, none of the nebula are easy and some are very hard. Just they way they should be. And so, in my opinion, there's no need to balance the entire rest of the game around Champions, too.