So far we can't really do anything to the enemy AI that I'm aware of, at least on the strategic layer.

The last update lets us tweak AI vision ranges, but mostly you want to be turning those up not down, so the AI is less braindead until you get really close.

What you're complaining about is the abstract enemy carrier capture rate - when it's not even being simulated and it just gets handed islands at a set rate. Sadly, I don't think we can change that yet.

If it helps, you can often just take the islands back, it doesn't get any particular benefit for owning them as far as I can tell... It's mostly only annoying when it reaches -your- islands quickly, and at least it does have to properly take those. A few turrets can delay it pretty well.

It is technically possible to mod the AI of the carrier. It's a whole other ballgame of complexity though