This just keeps coming up, and I feel like the problem is entirely with Crafty's use of the word Subdual. It should be called blunt or bludgeoning or something like that. No one ever has a problem with the mechanics or the visuals or anything else, it's always that giant ****ing hammers should kill people. The response is also always the same: they do. Against standard NPCs, all damage works exactly the same. Against special NPCs, the end result of both lethal and subdual damage is that they wind up unconscious on the ground and at the mercy of their opponents. The only difference then is whether they are bleeding or not, and whether they had to deal with grades of fatigued on the way.
The no damage to objects thing is a bit wonky, but I kind of see where they're coming from. Frequently, if a subdual weapon doesn't completely or nearly destroy an object in one hit, more hits are not going to have much of a cumulative effect, and I think that's the situation they're trying to model. If you want to smash a door or table, a sledgehammer will do fine. If you want to smash castle walls, that sledgehammer is a poor choice.