When you're on the mat, you shouldn't be doing judo, you shouldn't be doing BJJ--you should be expressing yourself naturally.
You might be using techniques from judo and BJJ, but you aren't limited to them or by them.
I'm writing this in English, and I am expressing myself, but I am not limited to English. English is not the only language that exists nor the only one I know.
If I want to express myself more fully, I might seek to learn another language.
The point being: Even though you might use techniques found in a certain style, you are not limited to that style's techniques.
The style is just an abstraction.
To express yourself fully, transcend style and all such artificial limitations.
Tao of Jeet Kune Do, remember? It isn't just a bunch of funny stick figures plus Eastern philosophy.
So what does this mean in terms of training? In order to train as comprehensively as possible, your ideal personal curriculum might consist of ground positions favored in BJJ, armlocks and chokes from judo, takedowns from western wrestling, leglocks from shootwrestling and sambo, wristlocks from hapkido, etc.
You should also learn why the various techniques work--there's nothing magical about them, after all. Like I've been saying, the styles aren't so important.
We take the facts that we know (minus as many unnecessary abstractions as possible) and apply those facts to the way we express ourselves combatively.
