Checked back on the game years later and I see little has changed for the better. One zombie hoard swept through and effortlessly destroys wood plank walls (plank, not basic), which take way too much time to craft. It feels like you should just accumulate resources and take all the time you need to keep shoving planks/stone into their craft stations until you can upgrade several tiers in one go. Because anything less is just flushing resources. Just let the daily hoard walk through until then.