Fitz would win. Greb would run into Fitz bombs. What is lost in translation on Fitzsimmons is the cunning nature of his fighting. Fitz could fient, act hurt, or change up his shuffle to time a bomb, then BOOM. It would be a great fight while it lasted. I would pick Fitz to win.
Well these two both can lay a claim to p4p #1 status, but I think the match up is not that close. Fitz is wrong for Greb. Harry can only fight one way - dirty and violent and on your chest. Fitz has more power than anyone Greb ever faced (?). Fitz by KO would be my guess.
Funny thing is, Greb fought well against heavier fighters. Greb outsped and outpunched the heavier slower fighters. Whereas, Fitz is not a heavy fighter. Fitz punched extremely hard, threw hard to the body and could take a heavy punch. Though I am a big Greb fan (note my username), I think that Fitz combines speed, power, durability and body punching. Might be too much for Greb, though I think that Greb would give it his all and go down swinging. Might be similar to the Bob Foster-Dick Tiger fight. Fitz by KO.