I've almost always felt more confident in front of a group than when dealing with individuals because I don't need to connect on an emotional level, just present the facts. Be respectful but confident; they're likely to push back harder if you appear indecisive. You've done the work and know the subject, all you need to do is present it and answer a few questions -- they can't kill you and they can't throw you in a cage, so what's to worry about?