First of all, Ko Sutemi Seiei Kan is not an off shoot of Shotokan,even though there are many elements of Shotokan that have been added over the years. It is an offshoot of the Koei kan style. Which Soke Madden Studied in Japan. Not Okinawa. During the 1950's and 60's.
Also with so many style being part of the organization, these styles have been blended in to develop the style further. I have been in the Ko Sutemi Seiei kan system for 25 years. I have been a student of Soke Madden for 17 years. Now, The original style that Ko Sutemi seiei kan comes,(Koeikan) comes from Okinawa originally. the Founder of Koei kan (Eizo Onishi) was a student of Kanken Toyama,from Okinawa. Soke Madden studied with Onishi directly and later with other masters in the Koeikan style. Then went his separate way for one reason or another in the late 60's Yes,at Soke Maddens dojo they do focus a lot on sport competition,but not all of the time. And many of us teaching the style teach karatedo as the total package. (self defense,kata,competition,research,etc.).
As far as Soke Maddens Jujitsu goes. His father was a merchant marine in the 20's and 30's and that is where while in Asian ports he studied Jujitsu from different teachers , Japanese and other. Before WWII broke out. He started teaching his son in 1942,along with boxing. Later on Soke Madden while in Japan studying karate do,was able to work on his Jujitsu training further and expand on what his father had started teaching him.
If you have any doubts of his qualifications. Visist his dojo. All of his certifications in karatedo and jujitsu,up to 8th dan were international organizations and Japanese organizations. Later after many years of being the same rank. He was given his 9th and later 10th dans from a group of his master students as well as several international organizations. He is in his 70's and fits the guidelines. He also has a 6th dan in Judo from the USJA. If you have anymore questions about the Ko Sutemi Seiei kan please feel free to ask.