I have seen many answers that agree with the first answer supplied, and simply add an extra bit of information (see this question, and this one, and this one). Should these answers simply be added as a comment to the first answer, or is it good to have multiple answers that are relatively the same.
Alternatively could users who want to supply an extra bit of info just edit the answer they agree with (given they have enough rep), or is it better to not edit others answers?
If similar answers should be added as comments or edits, should this be detailed in the faq section?