I don't know if you consider being a mere title holder the Heavyweight Championship, if so Roy Jones Jr held the WBA and if you don't consider his technical boxing skills as superior to Tunney then how about James Toney, who also briefly held the title before his win over Ruiz was changed to a ND after a failed drug test.
Toney nor Jones were ever the hwt champion of the world. Neither were as great a technical boxer as Tunney in any event.
Your first point is fair and that is what I thought you meant initially but I have a hard time believing Tunney was a better technician than Toney, your opinion though.
He does not have the body of work against premier heavyweights for me to place him in my top ten in that division.He is easily one of the top ten light heavies.imo