In many cases parataxis is a common form of expression
not only in the earlier language of Homer, but also in Attic prose and poetry.
So frequently in Attic prose with καί, τὲ . . . καί, ἅμα . . . καί, εὐθὺς . . . καί, and with δέ meaning
καὶ ἅμα ταῦτ' ἔλεγε καὶ ἀπῄει
a. Temporal conjunctions, as ἡνίκα, are rarely used to introduce such clauses, which often indicate a sudden or decisive occurrence or simultaneous action.
b. Thucydides is especially fond of καί or τέ to coördinate two ideas, one of which is subordinate to the other.
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].