I read a little more closely and I didn't find anything about having to mark the order field as distinct. There was caution about ordering by related models but not by regular fields like updated. It's not clear, but the section on postgres supporting `DISTINCT ON` makes me think even moreso that we can just distinct on what should be distinct, '`model_id`.

I ran some tests with my dev data and they look ok:
```
[localhost:2222] out: >>> Audit.objects.count()
[localhost:2222] out: 313518
[localhost:2222] out: >>> Audit.objects.distinct('model_id').count()
[localhost:2222] out: 56780
[localhost:2222] out: >>> Audit.objects.order_by('-updated').count()
[localhost:2222] out: 313518
[localhost:2222] out: >>> Audit.objects.order_by('-updated').distinct('model_id').count()                                                                                 
[localhost:2222] out: 56780
```
Here, ordering by `updated` before distincting by `model_id` did not change the counts.