I agree with that farming should be there, but it should take a large amount of time to get the plants grown, this way its not too easy and it would take more planning, if you think it makes the game to easy its simply something you do not have to do, and colony is the wrong word for it but i do think making a group where you can have people guarding your home base and also able to get them armed to the teeth while managing their needs or giving them the ability to access food laying around the area, this adds a new feature that adds a ton of realism, that’s what real humans do in these situations being a lone wolf in a zombie world is always certain death,management should be just grouping and commands like stay here and guard or whatever. maybe the ability to ration food to certain rates, 1-5 food items a day, or whatever also if the idea were to be taken seriously you could go into the npcs issues like a need for certain drugs and having certain skills so a preference on weapons and ammo, giving them the ability to make runs for food and drink or ammo, and having independent choices, own morals and stuff, these are all things that come with a group in an apocalyptic world