People today underestimate how clueless everyone was to grappling. You automatically assume Tyson would sprawl etc because we see it in every mma fight today. Royce would have taken him down, and submitted him with ease. Mike Tyson would not be Mike Tyson in the UFC. Especially at that day and age when no one had a clue what to even expect except for the Brazilians. Even in gyms you see a difference. Newbies know what you are trying to do to them but they can’t stop it. In the 90s they didn’t even have a clue at what you were attempting.
You can't downplay Tyson's speed, strength and aggression. He had been in lots of street fights and could very well be one of those guys with a level of natural wrestling ability. Royce was slow, and relatively speaking, weak. I could definitely see Tyson studding Royce's face with a brutal uppercut on the slow shot. Never know, but I definitely would not discount the speed and reaction time of Tyson against a slow fighter like Royce.