Should “duplicate” be used when the question is different, but the actual problem is the same?

Question

Should a Question be flagged as a duplicate if there is an existing Question/Answer that solves it, even if the way the user is phrasing their problem is different?

This is inspired by these two questions:

• Cannot obtain correct area values *With* correct projections
• What projection to use with Mapbox base/reference layers?

In each case, the root cause of the problem was the user choosing the incorrect ArcMap tool (Define Projection, rather than Project), and so the solution is the same. However, the problem descriptions are different because the issue was showing up later in their different workflows.

I can see the value of retaining each one, since a frustrated user of each type would Google for different terms to solve their problem. However, I also feel a little silly providing the exact same Answer twice (particularly since they were asked about an hour apart from one another).

Answer 1

If the best answer to the other question actually does answer the second question, mark it Duplicate, and add a comment to fine tune (not absolutely necessary but nice; a straight "this is dupe" can be off-putting).

If other question's answer is correct, but needs rephrasing to fit current context, then do so as an answer and still mark as dupe.

Answer 2

This issue came up in the Canonical Question question I asked a while back here on meta. How do you find that canonical answer which is the same when the question might be very different? My original question title for that was something along the lines of canonical answers vs canonical questions.

In fact, I actually voted to agree with the dupe flag on your second example but of a different question - an older and more highly voted answer that covers the same define/project explanation. As whuber has commented elsewhere, 'this might be the number 1 faq question on this site'. I had answered it myself a couple of times to varying degrees, but I'd never have found that canonical answer on my own. Someone beat me to flagging a question as a dupe using it before I was able to flag the question as a dupe of one I'd answered which had immediately come to mind.

I would suggest doing some searching before flagging though to see if you might be able to find a better prior answer (or question) - as I discovered, the first one that comes to mind might not be the best candidate to mark it as a duplicate of. PolyGeo covered some of that in his answer at the question linked above.