"They are a man and a wife."
Translation:He ovat mies ja vaimo.
In some languages "man" actually means both a man and a husband, but Im pretty sure not in English.
"Man" does mean "husband" in the fixed phrase "man and wife" as I've already stated. Look up for instance "man" from the online Cambridge dictionary and you'll find an entry titled "man and wife", and underneath that it says "If a man and a woman are man and wife, they are married to each other". Also note how the announcement of an opposite-sex couple's marriage traditionally involves uttering the words "I now pronounce you man and wife". I've never heard "I now pronounce you a husband and a wife" in that context.
Hey there =) I'd say while the above sentence is technically correct, and might possibly be used in some odd circumstances (almost implying that this particular man and this particular woman are not married to one another!), you'd normally hear this oldie without articles if the two people are married.
I've probably misunderstood you and am making no sense (sorry, it's very late) but where I live, "man" takes on all sorts of varied meanings, or replaces words like "husband", "boyfriend", "son", "person-doing-a-job-who-is-male" depending on context, of course. Ex. "Eey oop, Doris is bringing 'er new man around Friday!" (She's bringing her boyfriend) etc.
Another thought: I wonder if "wife" is related to German "Weib"? A fun old word is "fishwife" (job description).