I believe it’s not a good idea to have perks which only makes other perks’s traits better in such a direct way. Every perk needs to remain the way they are, independent. Because of that, I still insist that the way to go about the nimble perk is to change it’s name and turn it into an active skill with fatigue cost to activate, my main idea now is to transform it into a skill that when activated increases your mdef and rdef for a turn, as if your brother was spending all his power into evading blows for that turn. The bonus would still exponentially decrease with the more armor a brother had, making sense both in regards to realism and also being a balanced option.
Well then welcome in 5% RNG hell…