Building up a city defense is still completely pointless, and a waste of precious space...I have noticed a trend in this fall event, from the fact the barn and sunflower can be plundered if not motivated, along with the tactician tower (2-4% att defending) and other defense buildings for the city... FoE is trying to make those stats, once thought useless, more relevant. Wonder what future event buildings will be open to plunder...
Regardless of the stats you build, someone/s will always be able to punch through it, simply due to the existence of rogues & none of the basic era units really being balanced at all.
Either collect on time, and/or the odd time you can't, (ie: say you're resetting all the timers in your city), then use those 100's of self-aid kits that inevitably pile up in one's inventory to make sure everything gets protected by being polivated.
And for those odd buildings that can't be polivated, (ie: Cherry Garden set), just accept the very occasional loss... if your city is built properly, you won't even blink at losing 5-10 goods or a couple fps once in a blue moon.