I think Bruce utilized a few different styles, possibly ones of his own making too. Apparently he was frequently getting into real fights when traveling in Hong Kong, guys wanting to challenge him. Coming out from eating in a restaurant and some fighter would be outside taping his foot, the sign of wanting to engage. Bruce would knock him through a fence or something, then carry on. Kind of tall tales you would think, but his student, James Coburn, talked about it. Mixed styles might be harder to defeat? Maybe it was a good thing that Bruce passed away early, all the highly trained people looking to suffer him, a chance to become the next worldwide star.