The fastest to recover from that was certainly Eric, who wasn't doing something like this for the first time and would neither this be the last time.
Once S-day happened, there would be too many beasts and animals that would use live people as their cannon fodder in order to try and capture bases.
Sure zombie apocalypse would be terrifying, but the world after S-day was even more so, as people still had their clarity and did these things willingly.
Eric had already killed many more and would still continue killing others that was unavoidable. Even Machiavelli stated that a Leader needed to show cruelty to his people in order to lead them properly.
He was probably the one who could testify the most towards those words, as he had already tried to rule his people with honesty and love once and ended up getting betrayed by his closest people.
