I would've loved to have seen Frazier-Norton, but the other two I don't think would've added much to Frazier's legacy, as I think he's already beaten several fighters of comparable level as those (Mathis, Ellis, Bonavena, Quarry, Chuvalo, Bugner, etc.). To me they just would've been two more.
Frazier KO's them all. The only fighter out of this group that gives prime Frazier a legit fight is Norton. He's not knocking out Frazier but he was a decent pressure fighter with an awkward style. I don't believe Shavers or Lyle would have given prime Frazier any problems. Once again the tendency here is to use Foreman's destruction as a blueprint for what would happen if Lyle or Shavers fought Frazier is totally wrong. George Foreman never fought a prime Joe Frazier, and the fighter of the late 1960's would have given him a whole lot more problems as opposed to the fighter who showed up overweight and out of shape in Jamaica to defend his title. Both Lyle and Shavers have punchers chances against Frazier, but they wouldn't be able to deal with his pressure, pace and body attack. Lyle, based on his boxing skills probably KO's the 1973 conditioned Frazier probably in four rounds, not as quick as Foreman did. Shavers has the potential to KO the 1973 Frazier in one round, quicker than Foreman did, based on his right hand power alone.
frazier beats them all. tko norton 9 decision over lyle tko shavers 7 (even if ernie lands his best shot, frazier gets up). when ron lyle retired he was interviewed and asked if he regretted not facing frazier. lyle replied no because frazier was a bad man...
Norton has a slim chance. Frazier would be all over him and probably win late. Lyle-Frazier is more interesting and while I can see Joe getting dropped early, in the end he grinds him down and wins by a late TKO. I worry about Frazier against Lyle. Shavers was an absolute mammoth puncher and I can see him blasting out Frazier early. I'll pick Frazier in 5 but it would be dangerous.
Frazier Ko 2-3 rds over Shavers...Too much Fire and smoke Frazier KO Norton in 4....Frazier takes his time bobs weaves a zips that hook Frazier tko Lyle in 10...Frazier works the body and head of Lyle ,works, wears him and hooks him, Lyle down 2 times RSC