Some of the answers seem to be redundant (especially the late answers). Although there is a policy towards redundant questions, there is no policy on redundant answers. What are your opinions on redundant answers? Do you think that they are harmless?
3$\begingroup$ Just to add on to Martin's answer, there has been a fair bit of meta discussion on the VLQ flag. See for example here. If the redundant answer is difficult to read (e.g. extremely poor use of English, unreadable unformatted maths equations, or weird formatting throughout ThE answer), then feel free to drop a VLQ flag on it. $\endgroup$– orthocresolJan 5, 2017 at 9:33
If they are plagiarising another answer, then flag it.
Otherwise, judge it on it's own merit; usual flagging rules apply.
If it is rephrasing another answer, then it may just be easier to be understood by some users, hence it may have merit on its own. Let voting take care of that.
If you think it is a terrible answer, simply down-vote it. You may additionally leave a comment that this adds nothing to the arguments previously presented. The user then might overthink her/his answer and considers to extend or delete.
It sometimes happens that two people answer the same question with alike arguments at the same time. Oftentimes they then reinforce their argument and I see nothing wrong with that. If both answers are good I also see no reason not to upvote both.
From my experience most of these redundant answers are presenting a single statement without much proof. While they technically attempt to answer the question, they are not particularly helpful. That however doesn't warrant it to remove them. Below a certain score they appear faded and are easier to be ignored. I see no harm in keeping them around.