I honestly think that a good and modern Ruby team would have somebody like you, somebody like me and two people that want to switch to Ruby because they like the language better.
When it comes to the react/vue dev with some rails skills. Yes I get you, but a lot of those jobs are for people like me. I’ve been doing Ruby (and Rails) about 5 to 6 years of the last 10 years and JavaScript every step of the way for 13 years now (frontend and backend). I fit the full stack role but I honestly don’t believe that you need more than one of us in a Rails team. I would rather split the rest up between ruby/rails devs and javascript/react/vue devs.