He was also taller then Quarry ,Ellis,Bonovena,and Frazier
When the guys bigger then 3 different modern era champions,and comparable height to two more,its hard to say hed be "too small" to fight in the division
Not to mention Johnson was seriously built even with the crude training techniques of the day
Now imagine him with access to plio's,protein shakes,and a modern gym
Yoiks