There are several hundred posts in this thread, and do you think I should check each post for duplicates, previous versions, and everything else? There will always be abusers, no one is safe from this.

Do you seriously think that merit sources each evaluated post conducts a full analysis for the presence possible deletions, re-posting, look at the history of posts, check which posts they sent merit to before, etc?  You are greatly mistaken. Only in the most obvious cases, but not for every post.