If it seems like the sets are out of order, they're not: the artist sometimes will go back and redo some of the sets with lactation and/or pregnant variations. If there are any duplicates, please let me know.
I don't know what black magic this artist uses on his files that it leaves them so bloat that even a simple zip compression reduce the size of these images, this artist gallery has more than 30GB of total size (2600ish images), that when you lossless compresses all the files it goes down to less than 6GB.