I think it would be useful to introduce a new form of flagging addressed to users with 2k (5k? 10k?) reputation and not diamond moderators: flagging posts that require editing.
I'm thinking about posts that don't have issues with what they say (and thus don't deserve a downvote), but with how they say it:
- posts with poor English
- posts with poor formatting
- posts with broken links
The flags should also inform the post owner, so that they may attempt to address the issue themselves.
Posts with outdated or wrong content should not receive this flag. Commenting or adding a new, up to date answer should remain the way to go in these cases.