I think it depends on the answer.
(a) If the answer is (nearly) a copy or a subset (e.g., a link and some facts that are also mentioned in the previous answer), flag it. It should probably be deleted.
(b) If the answer is nearly the same and only adds trivial information or facts, flag it. It should probably be an edit to the previous answer.
(c) If the answer contains a personal and different review/rating, description of a workflow, warnings and caveats, etc. (i.e., it is a good answer), keep it. It can be very valuable to have several answers all recommending the same tool, because they add different perspectives.
- What would be the alternative? Such personal experiences shouldn’t be added to the answer of another person (the edit would be too radical), but I think they are too valuable to dismiss them.
(d) If the answer contains personal experiences like in (c) but it isn’t substantially different to the previous answer, it isn’t really useful to the question but neither should it be flagged/deleted. I assume this will happen rarely (maybe when both persons are writing their answers nearly at the same time and they had exactly the same use case).
If you see an answer that more or less contains everything you would have said, you should upvote it instead of adding an own answer. Edit it if some facts are missing. Only create an own answer if your personal experience with this tool could make a difference to OP’s decision.