Not to worry as he still has plenty of time to talk and the fact that he has said two words means he is capable and does talk, Josey didn't talk until she was one year of age and some take longer than that, he will learn words and phrases by you talking to him every day, tell him about your day and what you are doing, have a conversation with him like he was another person in the room and soon you will hear lots more than Cobi and Neptune, be patient.
Thanks for sharing some more pictures, he is one handsome fella.