An easy way to tell something is obviously
over-redacted is when a file has page after page completely blacked out while other pages show "the, and, when, dates etc." There is no way that a complete page of text does not include words like that or words like morning, afternoon etc. or adjectives, adverbs etc. So if all they are supposed to redact is names of victims or names still under investigation etc. then the blacking out of page after page is obviously complete nonsense.
But I think the over-redaction is part of their strategy to drag all of this through litigation and endless appeals and delay for as long as possible. Ultimately I wouldn't be surprised if they lose some appeal on a document and then try to over-redact it again in defiance of a court.
Also who knows how much more is in Florida, New Mexico etc. that "somehow" DOJ in Washington never thought to ask about.