When he retired, he was miles ahead of Tunney who did almost nothing in the division. I would put him ahead of Dempsey, to be honest. But definitely behind Jack Johnson and Louis and tho it irks me to say so, perhaps Jeffries, too.
For what it's worth, I find Steward's estimation of Marciano to be spot on, both the positive and negative. But for some, that is still blasphemy.
But what did he do at heavy? Beat an old, inactive champ over 2 10 rounders? Hell, Rocky did that 5 times (Walcott x2, Charles x2, Louis) and none were that inactive.