"Attack is easier than defense" is only true for a narrow set of present-day adversarial games that we're currently too stupid to see effective countermeasures and cooperative dynamics for. Those asymmetries are temporally local and always changing. If we truly live in a universe where attackers are favored in the long term as a result of increased intelligence, then intelligence should not have evolved in the first place.

I also want to point out that there is not a single living species on this planet where the intelligence gap between individuals of the same species is extremely large. Probably because when that happens, we'd speciate or die out for whatever reason. There is a small group of humans trying to concentrate compute and digital intelligence, and I think that will end badly if it continues.