From what I understand about how CRTs work, refresh is directly proportional to scan rate. Either one goes up or down, so does the other. In this sense, resolution is independent.
I was sorta under the impression that 15khz was a standard scan rate for monitors up until the 80s or so, and so I've often wondered how several vector games could be so much less than 60hz, for example Star Hawk: 224x256, 38hz refresh. The works out to be a scan rate of 10.34khz.
Really?