Not only the slug but you can edit the whole URLs addresses by using Permalink Manager Pro. It provides you a screen option which allows controlling how many URLs should be displayed per page. Also, it is possible to use the date filter and show the posts month on the list.
If you use two same permalinks then this plugin will prompt an alert below the custom URI field. And by using Tools -> Permalink Duplicates section, you can check and change the URL to keep all your website URLs unique.