If you go down that road you can pick at anyone.

Manny Pacquiao, yes he looked good recently but he's fought a ODLH who was never going to be anything like comfortable at 147 and he looked very ordinary in his last fight before that at 150lbs catchweight vs Forbes. Then he fought Hatton who suffered a heavy KO to Mayweather and then fought 2 people who didn't really have the power to KO him and then Pac looked great because of the damage Mayweather had done already. He was good against Cotto but he hadn't looked great since he was battered for 11 rounds by a man with plaster in his gloves. And then Clottey was just stood there throughout the fight with his hands up with nothing but surviving in mind.

Mosley, He was quite soundly beaten by Cotto (pre Marg) then he fought Mayorga who Oscar destroyed a few years earlier when Mayorga was fresher, and was getting beat (although somehow not according to the judges) when he produced a great KO and then he fought a man who it could be argued had built his reputation by cheating and was too good for him without his plaster to crash into his opponent.

You can look at most people and add a negative vibe and start to doubt them. I prefer to think of Mayweather since his move upto Welter like this. He battered a past his best Mitchell after his masterclass vs Gatti. He fought Zab Judah who caused him a few problems until he just figured out where he was going wrong, corrected it and then took over. Then he fought Baldomir who's biggest talent was his sheer toughness so he just used his speed and defensive skills to make sure of a very boring victory although he didn't lose a single second of the fight. He then took on a legend in Oscar out of his own (Floyds) comfort zone and despite going behind early on made Oscar start to amke mistakes and stop using the jab and then took over that fight too. He then moved back down to Welter and fought Ricky Hatton who at the time was in great shape and looked very good at welter IMO, but despite Rickys early aggressiveness causing a few problems that he could handle to be fair, he again took over as the fight went on and scored a great KO over an unbeaten fighter. He then retired and didn't fight for 2 years, came back fought a man who many had in the top 2 p4p and totally outclassed him for 12 rounds and the only time he really got caught clean, he stepped back and then floored Marquez. For me that showed his complete control in that fight against a man who was supposed to be the 2nd best counter puncher in the world only to Floyd himself.