this happens alot. I bought a 5 inch round piese one day and the guy went to back room and came out , it was in many pieces. I made many frags and they all made it. capricornis are very hardy. I would go ahead and superglue this piece to a new rock rubble or if theres a free place on the same rock to superglue that would be fine too. dont worry , it grows very fast one it acclimates. I would not try and let them grow together, probably not the quickest way.