Martial arts nerds
I think that to be effective you should be a martial arts nerd. The Filipino Warrior Arts system which I study blends Kal, Serrada Escrima from the Cabales style, and some Silat. However, I also go to any seminars that I feel could benefit me. You should always take every opportunity to put more "tools in your toolbox".
Don't take this wrong however, I believe that one should always take time to master a style. This is important, because it helps us pass it on to others.