I agree, my intuition is also telling me that’s it’s the て form of だ。Which could equivalently be explained as the て form of nouns.
As for the act of connecting two or more clauses using て (or で) itself, it can take various connotations depending on context.
Sometimes it’s equivalent to an English ‘and’, a comma, or a semicolon; other times there is a stronger causal connection between the two, making it a lighter version of ‘therefore’.
I believe OP leans on the latter case: they were N, therefore very few.