red houseNow, also consider for such a language that it, like many languages, does not mark number after numerals:
three houseWe can insert a quirk here. Let's say the language has some form of suppletive congruence with some adjectives (and maybe verbs):
little house(that's actually pretty much the suppletion that the cognates of "little" and "small", "liten"/"små" showcase in Swedish.) Unlike the Swedish case, this imaginary language doesn't just do suppletion in order to mark the plural, though, it also has an actual plural morpheme on top of the adjective - in essence having these adjectives mark plurality twice.
So, we go further: numerals do not interact with the suppletive part, but do interact with the suffix:
red little houseHere we thus see a limited amount of plural marking in the NP in addition to the numeral.
red-s small-s house-s
three red small house