I saw a post on dhammawheel saying that it is
"a fact that Visuddhimagga heavily plagiarizes the Vimuttimagga".
The Vimuttimagga has something of a cult following since it was translated from Chinese to English, possibly because it seems a simpler book to read. Does it have many truths?: yes large sections are accurate enough.
It also introduces several wrong ideas from the Abhayagiri sect.
The Visuddhimagga is roughly twice the length of the Vimuttimagga ..
It is true that Buddhaghosa knew of at least parts of it and some ideas in it are referred to as Keci (some) say ..“keci” is usually shorthand for those with the wrong take on some topic..
Both the author of the Vimuttimagga and Visuddhimagga used the ancient texts as references for much of their respective works.
There might even have been earlier texts that had a similar layout to these.
[I will add more later}
