Oh, and in real HA this poses an issue as well. Because when machine-3 calls Login on API server 0, then API server 0 will immediately watch the document and notice that machine-3 is now alive. However the API server on machine-1 hasn't had machine-3 Login yet, so it will still be dealing with slightly out-of-date data, right?
I don't think we want to have getting the right agent state dependent on which API server you end up connecting to.