GK Chesterton and Ezra Pound

... became friends as of 1934-1935.  In the 1935 letter, EP says "we are all three [EP, GKC, Hilaire Belloc] against Shaw, Wells, etc...."  Canto 45 is published in 1937.

St. Hilaire and St. Trophime in Canto 45 are probably puns on Hilaire Belloc and GKC (Trophimos means one who feeds or one who is fed in Greek, and GKC was notoriously well-fed).