My last hatch I had a little one who pipped and was quite noisy and active, but didn't progress at all. At around the 24 hour mark there was so no progress, and she was moving/chirping considerably less. I decided to help and found that the poor thing was unable to move inside because the membrane had died out too much. The chick did well and is perfectly healthy 11 weeks later. That said, she was the final egg in our incubator so I did not have to weigh her life against another chick's.
Ultimately it is your choice. There is a chance that the other pipped chick may have trouble if the humidity drops too low. It is not an easy decision. If you decide to assist, do what you can to mitigate humidity loss in the incubator, but keep an eye on that second chick just in case they end up stuck as well. Good luck and keep us updated!
