I'm sure this is true, but the documentation does explicitly say "Each machine should have a minimum of 8GB RAM" with absolutely no caveats about scale, so I think people can be forgiven for taking a quick look and moving on because they don't want to provision that.
That's a valid point, I've brought it up internally to improve the docs to explain what type of load this requirement is expecting. If you'd like you can create an issue for this in Github (https://github.com/influxdata/docs.influxdata.com/issues/new) to be involved in the discussion and change.
