I’m a little handicapped in this discussion because I’m only in season 5 of WD, and have only seen the first episode of FtWD - I’m dependent on Netflix for viewing and that means I’m about a year behind the current episodes. So I’m not entirely sure I’ve seen all the episodes you folks are talking about, and just keep it in mind I haven’t seen the most recent stuff (I am also fully aware there may be spoilers in this thread, so if I trip over one that’s my problem, not yours).
You’re right, everything done by Rick’s group is arguably self-defense (except Abraham beating Eugene unconscious for lying that one time). That part of what makes them good guys - they aren’t marauders. The average person IS going to have a hard time with killing other people, that why soldiers require training and even in combat some have trouble bringing themselves to kill other human beings.
I’d still argue some of it skirts the line of reasonable. That’s part of the tension - is or isn’t someone going to snap and go over the line? Darryl with the Claimers, for example - in some ways he fit in with them very well, if they hadn’t attacked Rick with him along he might well have gone on with them. Michonne was heading towards batshit crazy when she showed up with her two “pet” walkers. Carol - who used to be weak and submissive and crazy-protective about her child - has killed live people who were part of the group (to stop sickness from spreading) and a child (to keep her from killing again). Rick, who had a career dedicated to protecting others and defusing conflicts is having to kill people (yes, in defense) and has actually lead raids (again, in self defense). Carl shot his own mother which is a big taboo in most societies, even if he did it to save himself, his newborn sister, and potentially everyone else in the group. Even though he knew his mother would not want to turn and hurt her family, that could not have been an easy thing to do.
What keeps these folks on the side of good is that they keep questioning the rightness of their actions. If they stop doing that, that’s when they’ll take a moral fall. They are constantly having to do violent, horrible things to stay alive. They are all traumatized.
Actually, one of the horrible things about this show, when you stop to think about it, is that humanity as shown is losing people faster than they’re being replaced. Even if there weren’t cannibals eating people or marauders raping people to death, the population replacement rate would still be perilously low. Either people are going to group up effectively or they’re all going to die out.
So far, Rick’s group is the only one we see enduring, and even they have a scary turnover rate. They’re doing well enough to keep Judith alive, which has got to be hell between getting her formula/toddler suitable food and the problem that human babies cry when they’re the least bit unhappy, which can be deadly in their world. You don’t see a lot of other kids, much less infants, in this world. There should be more, because women are having sex and/or getting raped and I doubt there’s much effective birth control left (condoms, if you can find them, which are far from perfect). Where are the babies? I think we all know the answer to that - either cannibal food, or walker food.
The only kids that will survive are the ones like Carl, who are taught how to kill from an early age. I see Darryl as a sort of adult version of what a lot of them will be - pragmatist survivalists, stealthy, and ruthless. I sort of miss Merle, he was a good contrast with his brother. In many ways they were alike, the chief difference being Merle only really gave a damn about himself and Darryl is still able to care for others even if he has trouble showing that in most circumstances.
In a way, Darryl shooting the possum just outside Alexandria is a good example of this. I get the feeling that if it had been Merle he would have said “I’m hungry, this is my dinner”. Darryl said “we brought dinner”. For all that he’s a loner, he’s also part of a group and understands the give-and-take of being in a society.
Rick and the Governor are paired up, too - they both are ruthless in defending their group, they can and do exile people, execute people, enforce entry requirements and rules… but the Governor largely does it from self-interest, he builds a group around him to use for his own protection. Rick builds a group, but he’s also part of the group and will put himself at risk to protect it. Rick is capable of showing forgiveness, mercy, and changing his mind, his listens to those in the group instead of simply dictating.
You could probably keep going down the list, pairing members of Rick’s group with people they’ve met along the way.
A lot of the difference comes down to empathy - Rick’s group is still capable of considering how things look to the other side. “Eugene only has one skill, you’re angry with him for using it to survive?” They still capable of taking on dead weight - a liar with no fighting skills, a priest who is effing useless in a fight, an infant - because, for all their protests, it’s NOT just about survival for them. These are people who do, in fact, still want to be part of a society.
Long term, that is the only sort who have a chance of enduring - the trouble is all the other asshats and walker herds that could kill them before they succeed.