It wasn't MMA 1.0 vs MMA 3.0
It was a stronger, younger man beating down an older, weaker dude.
It was 1.0 VS 3.0.
Royce was unprepared for what and who he ws faciing.
Age can be a factor, but not always. Then of course we have Randi and Chuck; 45 and 38 respectively -which doesn't help explain away Royce not being better prepared when he fought at 40.
In any event pure jujutsu was always a dicey gambit-and it was originally made to work in connction with weapons. Stand alone grappling is as risky as Aikido or BJJ are- as stand alone arts- without striking and kicking.