Armstrong's run of 20 WW defenses in one year has him fighting 8 guys with over 20 losses, 4 of them had over 38 loses.
He fought Lou Ambers twice in that time and KO'd him both times.
Lou Feldman(95-38-15) gets two fights in that same time frame losing by KO5 and KO1.
He fought Bobby Pacho(75-48-15) twice in that time and KO'd him in round 4 both times; Pacho had won only 1 of his last 7 fights.
Howard Scott(61-38-10) had won only 1 of his previous 10 fights!

Today's fighters aren't allowed to hold titles in more than one weight division. Mayweather is a prime example of a contemporary fighter who fights in multiple weight classes at once. He moves up and down depending on the fights and paydays he can secure himself. If he were allowed to hold belts at multiple weights he would be doing so.