I got ten belts to hold up my damn pants but I'm talking about being champion. They can always make more belts. Who got more belts, Broner or Hank Armstrong? Forget about it.
Ward and Ward. He just had more dimensions to his game. Iran is tough as nails and a good puncher but Ward's more complete boxing game should see him to a landslide on the cards at any weight.
Ward was just better and wins a clear UD in an ugly fight. They started changing in the 80s, Ray Mancini-Duk Koo Kim (1982) and the cancelled Michael Spinks-Eddie Mustafa Muhammad (1983) led to changes, but I think it was gradual and depending on where the fight took place. So some places had day before, others had day of the fight. Same thing with 12 vs. 15 rounds. Leonard-Hagler was 12 rounds in 1987, a few months later, Tyson-Biggs was scheduled for 15.