Problem is, you essentially can’t trust people. Not even in a personal “do I know this person” way. But fundamentally people are squishy. If you squish them too

Problem is, you essentially can’t trust people. Not even in a personal “do I know this person” way. But fundamentally people are squishy. If you squish them too much, they’ll do things they never wanted to do. That unfortunately is why groups greater than 1 are a weak spot. In your scenario, you’ll never know if the last person increments an ID somewhere or did some other activity that adds compromises the chain.