Sigung Macias was Jimmy Lees student before the Oakland JKD school existed and until Jimmy's death. Jimmy never approved anyone to teach. Sifu Macias, Sigungs son, started training around 1968.Xue Sheng said:Point taken.
In rereading Dan Insanto's article and looking at the website you suggested, and your response I can see that there are more than 3 people that would be qualified.
I am certain the people that Bruce Lee approved have since approved others to teach. And his senior students, which he may not have approved; I am certain continued training and are worthy teachers. And based on the philosophy of JKD I am certain Bruce Lee would approve as well.
Advanced Martial Technology "without" certification.