Re: In zombie films, how come nobody has ever...
Well if you have a band of fighters, makeshift armor, shields and sword/chainsaws on the perimeter, an inner layer with long spears and and central firing squad with missile weapons (preferably rifles,) all in a hedgehog. When society gets reorganized, Macedonian phalanx tactics.
But taking this too seriously doesn't get the point of zombies, which seems to be fear of the mindless masses. Which means if they aren't too many right on top of "us" they aren't real, true zombie menaces.
Morals are what you do to other people. Other people, what we call society, are essential to human happiness. Therefore, morals are the path to happiness. My morals, your happiness; your morals, my happiness: It's a fair trade.