Thank you, I'm happy to hear it's been helpful!

I share that intuition to some degree, but I also think the specifics (particularly just how much autonomy the role involves and the target audiences) matter a lot here. It's also largely a question of what gap the comms person will be filling in the operation of the org. 

Let's say there's an org that is doing AI safety research and wants to disseminate their findings to the general public and/or policy makers. The comms person here will not be generating the substantive content of the messages (the researchers will be), they'll be taking that content and finding the best way to communicate it to their audience. In some ways, not being overly involved in the field here can potentially be an advantage (better able to identify jargon that more deeply embedded people get desensitized to, potentially able to better determine the frames of the target audience if they are closer to that group, has greater critical distance re: how the message may be received, etc), and in certain cases like working with policymakers, knowing more about the world the org is speaking to is more valuable than intimate knowledge of the world the org belongs to because knowledge of idiosyncracies can greatly improve impact.