We are in danger of going off topic here. Obviously Cockell is a metaphor for Loughran in this instance. Like Mariano, Carnera was answering a challenge from his #2 contender. Like Marciano, he saw off the challenge very convincingly, and it was seen as a low risk fight for him.
Now that is an interesting question. While I rate every champion of that decade, significantly higher then Carnera, he would have had a considerable size advantage over all of them. He would have been able to give Charles or Walcott or Marciano a difficult night, just by leaning on them. That would have given them something to think about.