That Pryor was an excellent fighter who beat an even greater fighter who was two divisions above his peak weight and in his 83rd pro fight?
PBF/Arguello depends on what era. If it's a 12 rounder, Floyd squeaks out a close decision. If it's a 15 rounder, Arguello stops him. This has been debated many times in the classic forum. My opinion has been the same for a long time.
Oh yeah. Without getting into the whole thing, look up "Panama Lewis" on google or wikipedia and that'll get you the story.
I think Mayweather beats Arguello at 130. I don't know about Mayweather beating Chavez though, or Camacho Sr. I see a young Camacho Sr at 130 and 135 giving Floyd all sorts of hell. That waste of talent is a tough style matchup for Floyd.