I definitely don't want "if a new chapter is uploaded, but it isn't the latest chapter, then don't show it on latest updates". For one thing, that would make chapter gaps even more annoying since I wouldn't see when they get filled. I also sometimes get "extra" chapters uploaded as X.5 significantly after chapter X was originally uploaded, and I usually want to see those.
Those particular issues could be resolved by changing to "if a new chapter is uploaded but it has the same chapter number as one that was uploaded before", but then that would make the situations where a group "snipes" with lower quality scans/translations than the main group worse. In those situations I usually just wait for the main group to catch up, and thus I want to see those uploads.
You could keep trying to narrow a definition further, but I think that making little compromises to reduce those kinds of false positives would necessarily also increase the cases where you wanted the feature to work but it doesn't.