..... But we all know that Funakoshi is the father of Japanese Shuri style karate just as Yamaguchi is the father of Japanese (Naha style karate) Goju. In that there is no flaw in my comparison. Do YOU find fault with that comparison?
Yamaguchi is not the father of Japanese Goju-ryu. In Japan (Okinawa included), there are 2 big Goju-ryu organizations, part of JKF. One is the JKGA (also known as Goju-kai, decsending from the organization of Gogen Yamaguchi) and on is the JKF Goju-kai (descending from Ujita/Kissaki/Uchiage/Yogi).
Gogen Yamaguchi claims he first learned Goju-ryu from an Okinawan gardner in the 1920ies. He learned about Chojun Miyagi at Ritsumeikan university and invites Miyagi over through Yitsuei Yogi an Okinwawn student of Miyagi, studying at that University. Later on through the years Ujita, Kissaki and Uchiage joined the Ritsumeikan club. (before and during WWII).
In 1952 Yamaguchi created the Goju-kai. In 1972 this organization was reestablished to crteate what is now called the JKF Goju-kai. In 1973, Yamaguchi was forced to resign fromn this organization. His main influence after Miyagi died was Meitoku Yagi of the Meibukan (Okinawan).
Within JKF Goju-kai, main infleunce (special advisor) were Eiichi Miyazato (Okinawan), Jitsuei Yogi (Okinawan), Kei Miyagi (Okinawan and son of founder). OGKK (Okinawa Goju-ryu Karate Kenkiykai) is part of JKF Goju-kai. JKF Goju-kai keeps to the 12 kata Miyagi instructed.
Yanaguchi's Goju-kai added a Takiyoku series for beginners and has a Hakutsuru kata. But the 12 other kata come from Miyagi. The term Japanese Goju-ryu is not correct in a sense that not everybody, even most of the Japanese practitioners are not part of this organization, and do not practise the Hakutsuru form or the Takiyoku kata.
Another thing Yamaguchi added was free sparring, jyu kumite but Morio Higaonna will argue that the seniors on Okinawa practised iri kumi, also a free form of fighting.
The format of the kata practised within JKF Goju-kai varies from sub organization to sub-organization. I have come full circle in the execution of the kata, so that the details now presented as changes are already familiar to me from past experiences.
To me, the only difference in regard to training is that when training with University students in Japan focus is on sport. When training with seniors focus is on manifestation of oneselve, with focus on authentic use of techniques presented in kata.
For me it's all Japanese Goju or all Okinwan Goju, take your pick. There is no difference in essence, only in focus.There is only difference in execution, depending on public and perception, and it's not related to wether it has lineage to Yamaguchi or not.