Against AI4, take in 2 Permafrost Shields instead of 2 Congeal, you can't imagine how much they can help you out.
Against AI3, you won't need that much congeal, you can remove at least 3 for 3 death recluses (switching 6 water towers to water pends) or adding 3 Ice Dragons.
You might as well consider Arctic Squids, they are almost like cheating against AI3 and AI4. (Not as good in PVP though, since they are the main target of CC of real opponents...)