Mitchell was the consensus no. 2 of the Sullivan era of 1880-1887, even scoring a knockdown over 190+ lb John L. (though Sullivan was insistent on it being due to balance), a knockdown over 176 pound Kilrain, as well as KOs over 170 pound Mike Cleary and 210-230 pound Herbert Slade in a private fight, all despite only being 150-170 lbs. A crafty boxer with a murderous punch, that also stings heavyweights. Would you favour him over any of the lineal titleholders from Sullivan and on? Maybe Braddock, Hart?
No. He also wouldn't beat any titlists and maybe not even any challengers either. Sullivan v Mitchell should be seen as the start of the HW title lineage but they shouldn't be favored over any champ that followed them. This is doubly true for anyone in the 20th century. If anyones on the table someone from the 1880s or 1890s. Braddock and Hart are on a completley different level. Both are very underrated. Got to remember LHW does not exist when Mitchell is fighting and in any other era he'd be nowhere close to the HW division. He did have a lot of pop for someone that light but its not neccessarily HW power.