It is stilll confusing for some people.
I think if your "primary occupation" is 3111-3112 on the EE profile, and you have a "work history" of 3111-3112, then you need the evaluation from the MCC.
However, if you graduated from medical school, but you did not practice as a physician or you will not work as a doctor anymore (may be a professor at a university noc 4011), then you can get it from WES.
Am I right?