Mighty Mouse all the way.
Volk is almost entirely a kickboxer.
MM has wrestling, submissions, and a full set of polished striking tools from either stance. He also mixed grappling with striking better than Volk or almost anyone for that matter.
MM is absurdly under appreciated. Dude was possibly the most refined full set of tools the game has ever seen.
Cardio
Speed
Elite tactics and strategy
Submissions
Wrestling
Footwork
Elite grasp of range, how to close distance, what techniques to use at what range, anglesof entry and exit, feints, rhythm, etc
All attacks and suitable defensive techniques symmetrically applied from either stance and shifting footwork that allowed to seamlessly integrate both without needing to reset
Strong mind
Work ethic
Athletic genetics
Hunger for continued success and improvement
Humble demeanor