Yup. New Light also falls in this category so you can have both Lights in tha party. This obviously makes RAV Light even better than she was before.
As for Snow he's apparently the best SEN (surprise!) with like 19k HP using Potent I think and 830ish attack. I'd say you can use him if you really want a SEN but I'd go with Light (COM), Light(RAV) and Sazh.