What do we do when duplicate questions go missed, both questions have good answers (full disclosure: I answered one of the questions in question), and both have been established and open for some time? This question was asked back in October and received some answers, and this one was asked just about a month ago (particularly disappointing because I recall thinking there was a duplicate when I answered it and couldn't find one!).
I flagged the earlier one as a duplicate because it came up in the activity feed this afternoon when it received a new answer and I incorrectly perceived it as being a new question, so I voted to close as a duplicate. As @Miniman pointed out in the comments on that question, we generally don't close the older of the two questions when there are duplicates, but it also doesn't feel right to close the newer one, being that it's been open for a month now.
If the general policy is to simply vote to close the more recent one, that's fine, but might it make more sense to merge the questions? I'm probably overthinking this and will go and vote to close the latter one as a duplicate anyway. Anyway, what do?