I'm not even sure that at 154 Floyd has a speed edge worth mattering. Norris was pretty damned quick. Floyd drops a UD but survives the distance.
Funny you mention that because even a natural 154 pound Norris has an edge in speed overall than Floyd did at 140 and 147 so at 154 its even more emphasized that Terry will have the edge in hand speed and footwork to easily cut the ring off.