I have been looking closely at the Baltimore set up because overhauling that organization under Angelos is an incredible job. I'm not suggesting that working for FSG is the same as working for Angelos family, but if you are a core part of the group that executed a (thus far) successful teardown-rebuild there, I have to assume you've learned a ton about how to reform an organization.
I ultimately landed on Mejdal as the better candidate because he had a very successful engineering career outside of baseball (Lockheed Martin, NASA), worked his way up from entry level with the Cardinals, became indispensable for the Astros, and appears to be the architect of the O's analytics program and decision making processes. The caveats here are about his role on some of the Astros misbehavior - hacking the Cardinals, what he knew about the cheating, and what he contributed to the er...problematic professional culture in the front office.
Mejdal is also rumored to be on the Mets' shortlist. He's 100% worth offering an interview if only to pick his mind about how he assesses the Red Sox at present. Before hiring, you'd want to be comfortable that he won't bring that old Astros culture with him.
Back to Rosenbaum, I think she's also worth a close look and an interview in order to understand the scope her responsibilities and expertise. Her job titles in scouting and operations are enticing, but she would seem to be (from the outside) the junior member of the Os' front office leadership. In an interview, I'd really like to hear who she'd recruit to build out her team.