For the record, I loathe this diagram, I loathe the poor, cherry-picking scholarship that led to this diagram and I loathe the second-rate scholarship that has led to many ignorant junior college English professors embracing this diagram. I'm not the least sorry if any given reader finds this insulting. Campbell was a hack, right up there with other pseudoscientists like Wilhelm Reich and Erich von Daniken.
But of course, if you promote a theory that every myth corresponds to one ideal, then sell this theory to a million would-be myth-makers, the result is an endless string of shit Hollywood films about chosen messiahs that are called forth to an adventure because it is 'fate,' preferably with characters who are orphans and yet somehow specially manufactured so as to be the only proper saviour.
Thus I did leave out the most obvious and annoying solution for the player + dungeon problem . . . make one of your players "the one" and then pour convenience, ability and invulnerability all over the character like a big sploosh of anointing oil, guaranteeing success in all endeavours.
For the few young here who haven't had time to know better, I warn you away from theories that try to hammer human culture of any form into a single mold. The result in the end always turns out to be an unsightly mess mashed into a round hold by a wet, dripping mallet . . . but we shouldn't expect that to keep some 'scholars' from trying. The world seems much simpler if it is neatly packaged up in a bow, even if it takes 200 pages of incomprehensible language to 'prove' that it is so.