They probably have never heard of Rodrigo Valdez...he was pre-80's of course. I the same right that Valdez decked Monzon with landed on Hearns' chin it would have ended the fight. Valdez was too much middleweight for Hearns and would have hurt him and finished him off in 4. The height and reach advantage of Hearns would have bothered Valdez only for about 2 rounds..he would have hurt and decked Tommy in the 3rd, and finished off the wobbly Hitman in the 4th for keeps.
Hearns wouldn´t KO Valdez. Too much of a chin. On the other hand Valdez could KO Hearns. Hearns would be able to outbox him, he has the advantages in height, reach and skill but Valdez would connect and I bet when he does it´s over.