Interesting topic, however hypothetical it is. One point that I think clearly differentiates tournament fighting of any description to that of "real" fighting is the prior knowledge you have of your opponent. No doubt the professional fighters spend countless hours studying their fellow combatants in order to study their strengths and weaknesses, not something that you can do with the same amount of depth in a street situation. So they take this information and train accordingly, with that in mind you'd have to ask yourself how much of the fight is purely based on the fighters skill in the moment and what the specific pre-fight preperation is worth. If Rick Spain had to fight Royce Gracie back in the day then you know he would have done everything to finish the fight on his feet and Royce would have waited to take him to the mat.
Interesting to hear that Rick is a blue belt, I've heard instructors suggest in the Brisbane kwoon that Rick is better than John Will.
"A basic tenet of the Shoalin teaching, which is an echo of the Buddha's advice to his followers, is that one should not accept anything on faith alone, nor on the reputation of the masters, but practise the arts diligently for a reasonable length of time, and then assess the results according to one's understanding and experience" Wong Kiew Kit, The Art of Shaolin Kung Fu.