GUYS I FIGURED IT OUT
I FIGURED OUT HOW TO FIX THE JUMBLED POSTS
Okay, so if you’ve noticed that when you go to your front page, a lot of old posts are randomly resurfacing and your new posts are getting buried under them no matter what you do, there’s a REALLY EASY fix for it!
Just go into the resurfaced old post, and edit it in some way. In my case, I added a tag that said “test”. Any kind of edit to the post will be fine as long as you save the changes.
Then I reloaded my front page and behold! The old post was back in my archives where it belonged!
(Incidentally, if the theory that this behavior is caused by posts getting flagged and unflagged, then you can see which posts of mine tumblr’s bot thought were nsfw by looking at the test tag)