Well, Jacques + Bronze is the strategy that dominates the Game. Its not a>b>c>a as it should be in a balanced and strategic game. I think we all agree on that fact.
But does Jacques have to be nerfed? I would like a nerf even though I play him, don't get me wrong, but the answer is no. They do not have to nerf him, there are other ways to make jacques life harder. Here are some small suggestions:
1) Attribute loss on getting injured: The Jacques + Bronze siege for golden walls implies a couple of loss runs where you just lower the amount of golden units. If it would start hurting by loosing 1 Attribute point permanently, player would look for different strategies then simply wipe 10 times to open a big one.
2) Fielding Power: At the Moment you just need to be 3/4 Level ahead to field bronze against someone. Otherwise you use angel or a little bit of silver. If we raise the neccessary power one needs to field for a fight they would think twice before attacking at Jacques+Silver all the time. Problem is that the Jacques + Bronze means rare ressources are useless. Player don't attack reasonable to plunder or at least not sit on costs. Today they just attack because they can, because they don't like your name, or what you said and so on. They don't have to look at the costs, its just Bronze. Higher neccessary Fielding Power would change that behavior a lot.
These are just two ways to change the dominance or at least put it at some cost. Because the most annoying part in the Jacques + Bronze concept is, that people dont even have to take risks. If they fail or poorly execute, they loose nothing.
Jacques would still be OP and still decide the game. But at least usual Jacques player would stop to attack anyone at any point for no reason.