I doubt many WWs in the early 2000s would submit Royce. It's possible they could, but that's like the hardest route to victory. Just force him to stand and get a KO/TKO or dominant UD win. Or even take him down and do some GnP and control him, but don't play his game with too many scrambles going for subs. No reason to risk that when there are easier ways to win. Don't try to beat him in his strongest area.
Renzo had a lot of losses in the early 2000s but Sakuraba was the only guy to submit him. Guys like BJ Penn just walked out and KO'd him. I think young BJ might have subbed him or at least won a UD in a grappling match, but why risk it?