Earlier quoted context omitted.
It won't happen because those criteria are antithetical to the purpose of a union. Unions are about solidarity as a working class against corporations. It doesn't work unless members see eachother as on the same side regardless of perceived competence
I'm not on the side of the dead weight I have to pull at work. Not ever. I'm not on the side of the useless union official who makes a multiple of my salary (taken out of my paycheck) for preaching "solidarity" to me. Results or GTFO. Union people talk like you, which is why Google doesn't need to convince me that unions are bad. Unions have already done the work for them.
Obviously there'd be a lot of complicated details to work out so the employer can't actually treat the union like it would a regular contracting company (e.g. a tool to keep its responsibilities to labor at even greater length, and fire with even less care).