He beats the ever living shit outta Josh. Takes Mel apart at any weight. Probably too small for Jermain, but the class gap is so huge that Napoles would probably be more competitive than he should be.
Jermain somehow nearly lost to Stinky Spinks. I could easily see him dropping a decision to a fat Napoles
The best matchup out of any of these is Napoles vs Mel at 140. Mel at his best was good enough to be competitive with any junior welterweight in history, and that includes Napoles. But after about 6 rounds of Taylor being competitive, I see Napoles' pin point accurate power punches starting to take their toll, and Mel gets KO'd in 9-10.
I'd take Jermain over him just based off size. Could be pretty competitive, though. He absolutely butchers Josh and Mel. Both too defensively naive to get anywhere with Napoles and both just open themselves up too much for Napoles.