Despite the general anonymity, the narrator names Francois Villon (see image). However, most of the others remain a guessing game. A rugged Edwardian Englishman's dreams will end in ice and hunger. Shackleton? The rugged Englishman converses with a "...dark man in a form-fitting glittery coverall..." (All One Universe, p. 111), whom I take to be fictional.
Kit Marlowe is mentioned although not present on this occasion.
Another man has "...bony head, craggy nose, ruddy beard..." (p. 112) - and both ears. Shouldn't he have had? The narrator quotes, as if relevant:
"The light, the coals, like the sun." (ibid.) - and then quotes the bony-headed man himself as saying, in Dutch:
"'White, Theo. All colors go up together in the white heat." (ibid.)
Van Gogh? (Later we learn that Bony Head painted self-portraits.)
A French-speaking European in early nineteenth century garb with failing sight sips wine while conversing with an Arabic-speaking North African Muslim who drinks fruit juice. The Muslim remarks that nomads revitalize civilization but later in turn become corrupt and feeble. The European compares extinctions in other species with human degeneracy.
Villon sings of Harald Hardrada dying at Stamford Bridge and mentions Simon Bolivar whom the Time Patrol helped.
The John Bullish Englishman who enters next is named at the end of the story - Winston Churchill.
There are more. We can discuss which characters could profitably visit the Old Phoenix but we should mainly appreciate how well Anderson blends together those that he does send there.