Since you are copying the meta SO thread here, we should also include the (very) important exception to the guidelines you cite. This is a screenshot, taken on March 16th, 2014 of the [second highest voted answer][1] from the same Q&A:

![enter image description here][2]

While merging is no longer an option (mods, please edit this out if it still is), the point about guiding users stands.

So, follow the rules above in general but avoid deleting questions closed as duplicates because they are useful "guideposts". The more duplicates there are, the wider the variety of possible queries that will lead a user to their answer.

  [1]: http://meta.stackoverflow.com/a/58844/203101
  [2]: https://i.sstatic.net/KZfZF.png