So this isn't OK but 50 dupes are? I don't understand why dupes shouldn't be deleted on sight. The only thing they do is spread out user favorites through multiple images for no good reason. Dupes should serve their sole purpose of saving dupe hashes so they can't be reuploaded again.
Dupes happen too rarely to be of much consequence. Also they're often not identical dupes, and small differences can mean one person likes one version better, and another person a different one. What's the problem about people favoriting a dupe? Unless it is so clearly inferior as this one, it really doesn't matter at all.