2006[1, "4. THE DEFINITE ARTICLE"] tells that "Collective nounts" are used with THE definite article. Examples: "The French, The army, the
clergy" They are used with definite articles when one is talking about a specific group.
Why do wiki's "List of collective nouns by subject A-H" list
sall collectives with an indefinite article?
For example, "An army of ants"? because it was not talking about a specific army of ants
But you can say things like ''The army of ants I saw yesterday was very interesting to watch.'
PRACTICAL REALISATIONS OF ENGLISH DEFINITE AND