Tua?! Tua could potentially put Norton down as quickly as he did Moorer. I could see Norton beating the likes of Coetzee, Weaver and Mercado. All three had tremendous power.
We could be talking the hardest puncher Ken could literally stand up to in terms of actual connections or the hardest puncher whose power Ken could confidently avoid via a superior skill set. In terms of sheer absorption, we have a range between and starting at Ali, Holmes all the way up to Foreman, Shavers and Cooney. I think that nicely narrows down the possibilities. Okay, getting off de fence, I’ll throw up Ron Lyle - I could perhaps see Ken avoiding any fatal bombs for a points win - perhaps even scoring a later round stoppage. But..if Ronnie lands like he did vs Foreman and Shavers, I don’t think Ken passes the test in terms of actual absorption.
Norton lost to Foreman and Shavers who are universally recognized as the hardest punchers in boxing history, I wouldn’t those loses probably ruined his chin though.