A major question underlying this: What skills are transferrable from the ISS to a Moon landing? Will experience count? An astronaut who's been on an ISS 6 month rotation will have spent less than 2 days in a spacecraft (that's not the ISS.) Working in zero-g for 6 months isn't really relevant to Artemis until later missions involving Gateway. The most applicable skill will be spacewalks. Very different from moonwalks but both involve operating in a spacesuit for 6 hours and more.

The biggest skill set will be the ability to master skill sets, especially disparate ones. The astronauts who demonstrate this best will be the best candidates. I nominate Jonny Kim, he mastered the skills of being a SEAL and a physician.