it wasn’t ahead of its time at all. People had been cross training LONG before Bruce lee turned up. gene lebell for one. Also chuck norris combined Multiple martial arts into his own style. Joe Lewis (before he met lee) had wrestled as a kid, boxed, done karate and judo."Your point being? "
If you don't see that as ahead of its time, I got nothing else. We're speaking different languages.
dan innosanto (before he met him) was a black belt in Kenpo who had also trained in Philippino martial arts.
so yeah lee may have been the loudest but he certainly was not the one who invented the idea