Should collective nouns be used with definite article "THE"?

[vgv8]

[1, "4. THE DEFINITE ARTICLE"] tells that "Collective nounts" are used with THE definite article. Examples: "The French, The army, the
clergy"

Why do wiki's "List of collective nouns by subject A-H" lists all collectives with indefinite article?
For example, "An army of ants"?

[1]
PRACTICAL REALISATIONS OF ENGLISH DEFINITE AND
INDEFINITE ARTICLES
http://webspersoais.usc.es/export/si...MAR/GRTIP1.pdf

[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" lists all 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
INDEFINITE ARTICLES
http://webspersoais.usc.es/export/si...MAR/GRTIP1.pdf

2006

[Tdol]

The text that pdf link points to is confusing. Starting with the title, it doesn't instill confidence and then it begins like this about Modifiers and Substitutors:

All of them share one main characteristic.
However, some of the groups act only one way, some limit the reference of the noun
as deictics do and yet others can represent a noun or a phrase with the same form or
with a different form by means of contextualised associations.

It hasn't even been spellchecked properly. It lists taxis as a singular noun.