I have seen several times a user, mostly a newbie, post an exact same answer, i.e. in this question, What would be next after minor, major, …?. The chances are either Ugh didn't read the previous answers or he is not fully aware of how to post an answer. And not surprisingly, the post appeared in the review for Low Quality Posts.
Now, if you click on Recommend Deletion on the post, you see the below pop-up and unfortunately there is no warning for this situation.
I think it would be better if we could have one more warning/basis for Recommend Deletion such as:
Your answer has already been posted by another user and doesn't provide any additional information.
What is your thought about this? Will it be OK to just click on No comment needed for this answer?
One more question: Wouldn't it be better to create one more warning for an answer which is the opposite of a link-only answer, for example:
This answer doesn't provide any reference/research (or link) that can support it...
I think this happens more often than a duplicate answer.
Edit 1: This answer to the question, What is toilet? is not an exact duplicate but it doesn't add any additional information. It is not a wrong answer, either.
Edit 2: I do see more often duplicate or no-research/reference answers than thank you answers or link-only answers. Thank you answers could be flagged or recommended to delete very easily without any comment because it is blatantly not an answer.
I am proposing to change the pop-up to include more useful warnings, i.e. deleting This is a "thank you" comment (or possibly This is a different question posted as an answer) and creating the two suggested comments above.