I'd be curious to know to what extent striking or wrestling-based fighters practice jiu-jitsu for MMA. I figure everyone learns how to create space and get back to their feet from the bottom; defend/execute pop-triangles and armbars from the closed guard; defend against/avoid guillotines; and throw in some RNCs and, if you're a wrestler, some head-and-arm chokes, and that's the world of jiu-jitsu for the non-jiu-jitsu-based fighter in a nutshell. That still leaves guard passing, guard recovery, sweeps, which IMO are woefully underdeveloped in MMA.