As I said earlier in the thread, I can see the merits of having 0% defense. Not giving any land to defense means you can fill it all with useful buildings for goods or whatever you want. With the new 'city reconstruction mode' coming out Soon™, it will be even easier to properly plan and layout a perfect city with no wasted space.
With the data presented here, there is a strong case for going the 0% defense route. It's not for everyone of course, but if people don't care that 1-2 neighborhood thieves plunder a single building a couple times a week, then they can happily give up whatever defense they have and just put down production buildings. That's not even counting that just collecting on time means there is nothing to plunder anyways, which is the best defense in the game.
A case could also be made for using the city shield to stop a really annoying plundering neighbor if you wanted as well. I have over 300k tavern silver (and rising. I don't spend it unless a quest asks me too. I just don't think about it for boosts I guess). I could sit inside a city shield for weeks if I wanted, with 0% defense and just pumping out goods and whatever else with no issues.
Now, I won't do that because I like a defense. Not because I want to deter attacking, but because I like watching people fail when they do attack me. I have a solid defense% and I also have Progressive Era and soon Modern Era troops defending my Industrial Age city. Always fun watching people get slaughtered. Bet they're surprised to see those advanced troops hahahahaha. Sadly, I haven't been attacked in over a month and a half now. So, technically, all my space wasted on defense buildings (SMB for one) could be better used producing goods and I would have had far more in the 1.5 months than I made while having all my defense.
Anyways, I still think this is a good way to go for people that don't care about the few times they may get plundered.