Re: 2 rescue capsules
That's a good point, but I have to wonder if enough docking ports are available on the ISS to allow for 2 Soyuz capsules, a Progress resupply craft, and the occassional Shuttle. There's also the need to either extend the Soyuz's on-orbit lifespan or to increase the production and flight rate. The situation you describe with a "Big Soyuz" would be the same if the CRV was the lifeboat.