No doubt at least some of those purporting to archive are shills.
The mega.nz site run by "Germanarchiveanon" is a fake site that contains only thumbnails. I'm not sure if it was always like that, but that is how it is now. It gives the illusion that things are being archived and anons who are focused on other topics are dissuaded from doing a full investigation. This shill periodically dupes anons by posting a sexy librarian pic.
Anyone can easily confirm that the mega.nz site listed at the top of every bread is fake. Download a zip file from the past few months and check any image directory. Sort by image size and look at the largest.
For most of the media files on this board, thumbnails are useless (apart from a few memes).
I do not know of ANY actual archives for the board.