Yea, the problem with “crazies” style zombies is that it only supports an “outbreak” scenario, not an “end of the world” scenario, and as you note over a very short amount of time the vast majority of them would starve, and only a few would that could manage to forage would be left to be a persistent, but occasional threat.
The answer to this is to leave them crazy, but intelligent, so they could forage inteligently (if they can open cans, they should be fine) There’s a technical problem with this, the AI code in the game is nonexistent, and no one is even working on it at the moment because the lack of AI isn’t a serious hinderance for most of the enemies. (arguably CHUDs fall in the same category and should have some intelligence to them, so expanding CHUDs might be a path forward for this sort of thing.)
I don’t have a problem with this concept in principle, but I don’t think it’s something we’ll be pursuing soon. That having been said, if someone is on fire about it, they can feel free 