Can be used, the meanings, however, are somewhat different. " A man and woman" in Chinese means, "一對男女", "A man and a woman" in Chinese, "一個男人和一個女人". I was assuming the Poet emphasizes the process of coming together rather than the existing state as he used "a perfect pair" after. But all depends on the poet's choice ~~ Thanks heartly 肖莊 for this interesting discussion!