The point I was attempting to make was that in terms of difficulty for the young dog and/or new owner getting the puppy accustomed to strange surroundings and learning simple commands via a puppy class would be a logical first step. Then the new team could try the (in my opinion) easier of the performance venues which I felt was rally. Then after getting their feet wet in rally, try the obedience ring with its more regimented movements, off leash exercises, distance exercises and less leeway for errors. With each new venue worked the new team could gain confidence and hone its skills. I do hold the opinion that working and competing in one would help move the dog and owner into more difficult venues.
The CGC is an excellent way to introduce a young dog to being touched by strange people, meeting strange dogs and in one of the sub tests, being left by its owner.
Rally Novice takes it up a notch to the dog heeling with its owner around a ring and doing simple movements. Multiple voice and hand signals and verbal praise are encouraged. The judging is less strict than in obedience.
Novice Obedience takes it up another level. Some off leash work, no verbal praise during the exercise, some distance work and the dog is expected to be more controlled and the performance more "crisp". Also, no do overs. The judging is more critical.
It was my experience that what my puppy learned in puppy class enabled him to move to the CGC to rally then to obedience with growing confidence and improving performance. Learning one helps learn the other. JMO