UFC rules and cage are lot worse enviromment for submissions than Pride ring, so it is not just "evolution and improvement" . With 10 minute rounds with enough time to work, restarts in the middle with no wire barriers to limit movement of your body on the ground, and with GI kimonos allowed, emphasis was much bigger on submission game in Pride. Nowadays in UFC nobody wants bottom position any more, because he wold be easily cutt by cheap elbows and got his head pinned against the fence. Nogueira and Pride guys were foremost fighters of different rules and enviromment, and in that environment their skills and habbist would be successful. In terms of footwork, it is now running around and dancing on distance in big octagon, while in the ring it was a lot more direct.
Size matters less in the ring.
It is a lot easier to reach taller longer guy in the ring where he has less space to move and where he can be closed to corners. Also, with no wire fence, weight matters less becuse you can not use size of your body nowhere that much as in the cage to controll the body of your opponent and enforce.
That's why short guy with brick in his hands like Igor Vovchanchyn, had no problems to reach full sized 190cm HWs like Valentijn, Yvel, Goodridge, Kerr, Baretto in the ring, and they were not able to pinn his body against the wall and enforce size.
One dimensional game + strenght like Lewis, Tuivasa, Rozrnstruik, JDS, Ngannou is just as enough to carry you to the top of modern UFC.
