The problem i have when we do these fantasy matchups is we never take in consideration styles and how each fighter performed against said style. For example, say what you want about Oscar but he never seemed to struggle against slick fighters (Floyd and Pernell, two of the top 10 greatest P4P). On the other hand, he did struggle against fighters who were extremely athletic and those with great jabs (Mosley, Hopkins, and Quartey). Ennis has yet to fight a fighter who possesses the speed, jab, chin, footwoek, and grit of an Oscar but the closest we saw was Zayas( who hasn't reached his peak yet). The clash of styles is interesting since Ennis posses elite athleticism, jab, timing, switch hitting, and the ability to fight at all ranges. While Oscar possesses elite footwork, speed, chin, and relentlessness. At 147 and 154 this would be one of those trilogies where Ennis would probably win the war. Oscar had a tendency to take his foot off the gas while Ennis fights the same way from round 1 to 12.
Would never happen. Floyd needed 6 years to fight Manny and Floyds camp invented "side of the street" promotional company differences as an excuse to duck opponents. Floyd would never fight Bud Crawford.