In Chapter 1 of Animal Farm, why does Orwell describe "Beasts of England" as a "stirring tune, something between 'Clementine' and 'La Cucaracha'" ?

Perhaps George Orwell found both "My Darling Clementine"
and "La Cucaracha" highly stirring songs himself, but I believe what he really meant to
say was that "Beasts of England" could be sung to a tune that is quite similar to the
other songs. I have always found Orwell's mention of this passage highly amusing, since
it does appear (at first) that he is comparing the relative emotions of the songs. But
after singing the words of "Beasts of England" to the tunes of the two other songs, it
becomes apparent that Old Major simply borrowed a well-known song (or in this case, two)
to which he attached his own lyrics.