I wouldn't count a duo Connie as a much greater force. It's far larger and has a lot of things that can go wrong. If something catches fire or power routers blow then one of those two will have to be running around to do damage control. It's large enough that a dedicated engineer should be required during combat.The Connie is also much more of a missile boat, having many times the missiles of the redeemer.
i think the redeemer will shine when fully crewed. When soloing or duoing, the Connie will be slightly better. When both are fully crewed and used correctly, both will be good ships.
The Redeemer is small in comparison. The turret gunner may need to get out for fires, but they should be contained easily.