Not as simple as that Brooklyn.
Duran won one and lost one against Leonard. It was the rematch where Leonard knew that Duran had trouble with weight and would balloon straight after a fight. He waited for him to balloon and then challenged him to a quick rematch knowing he would be weak with such a quick weight loss. Duran then couldn't continue in the fight, not because he was beaten, but because he was exhausted. When they fought again nine years later Duran was a spent force after losses to Benitez, Hearns, Hagler and two others. So it's fair to say the jury is out on Duran v Leonard when Duran was in his prime.
Also, when Hearns lost to Leonard in the 14th, Hearns was winning the fight. It was a late TKO for which Leonard deserves full credit, but there was very little between the fighters. Their rematch was a draw.
Also, the win over Hagler was a split decision and it was in the twilight of Hagler's career (his last fight). There was nothing between the fighters.
So taking the contrary view, Leonard drew with Hearns, lost to Duran and could only manage a SD with Hagler. Pryor beat Hearns as an amateur, Hearns destroyed Duran, Duran beat SRL so Pryor wins.
Man those were the days. A single division with Benitez, Hagler, Hearns, Duran and Pryor. The greatest era of boxing!