Do you prefer armor or attack?

The longer the "tank" lasts, the more intact the same-hitting stacks will be. If you enter the Dragon Utopia on week 3 with Craig using parameters 17-3 without defense, it's a wipe or at least heavy losses, because the tanking will end right after the gold dragons strike, and the green and red ones will bite the hitting stacks; after that, such high attack won't help, as there will be no one left to fight.

So you mean the skill works equally well regardless of defense parameters, as I understand it?
For some reason, lately I've been doubting its effectiveness and haven't noticed any benefit from it
ps by the way let's play again

From everything said above, the conclusion is that the most optimal option is to get both skills and level up the hero with a focus on attack; you hit hard and take 15 % less damage!
If that's not possible, choose based on your needs