What you make of your experience is what matters. Karate Kid far outweighs both Orion & Thor in h2h skill, and he's only 20 or so years old.
Orion's 200-300 years of constant battle and training, taking it seriously and having a natural ability to fight>Thor's 2000 years of goofing off and being punished and sent to Earth for a few hundred years until he matured.