I think you’re right that if a voter — or even if the vast majority of the voters — wanted, say, one pseudonymous Twitter shill but not two, and one VC but not two, and one person from Asia but not two, and one person from USA but not two, etc, that approval voting doesn’t really give them a way to express their goal. All of the voters could’ve wanted that, but then could’ve ended up with all five winners in the same category, just because there is no way in approval voting to express that this is what you want.
I’d like to point out that ZIP 1014 included a couple of diversity constraints! Namely that at most one ZF-affiliated person and at most one ECC-affiliated person could serve. Since that was established up front, the result was that exactly one person from each category ran (Shawn/mineZcash, affiliated with ZF and DC/alchemydc, affiliated with ECC).
I can think of two brainstormy ideas for how to evolve this process to allow voters to choose diversity as one of their goals.
One is to replace only one or two MGRC candidates at a time, as I previously suggested for the reasons of continuity and ability to execute long-term plans. But it would also allow voters to say “ok we’re going to have these three or four specific people, and which one or two additional people do we want to add to complement them”. So as a voter you could — if you wanted — think about which of the candidates would be different from and complementary to the continuing members.
Another idea is that candidates could run on a “ticket”. Like you could imagine a candidate saying “I’d love to do this job alongside Alice, Bob, and Carol because I feel like I could add a lot of complementary skills, background, life experiences, network, personality, etc and we would work well together as a team. But if the other members are going to be Dave, Ed, and Fred then I think they already cover what I’m good at and I don’t think i should be added to that team”.