Leonardo da Vinci
Chronology. Whoever put this together did it in a thoughtless manner. Even if you are not very familiar with the works, it is patently obvious that a "study" for a painting is earlier than the painting itself. There are several instances where the studies are shown after the painting.
Put all studies for a particular work immediately before the work itself, for easy comparison. Don't separate them with a drawing of a machine that is unrelated.
Be aware that very very few of Leonardos paintings are reliably dated. This means that the studies are not dated either, unless they happen to be very small and on a sheet that has other dated material. THis means that there is leeway in the arrangement. If your source dates the drawing of the head of an apostle that appears in the Last Supper at a later date than the Last Supper itself, then you know your source is wrong. Likewise there is a study of architecture which pre-dates the Unfinished Adoration of the Magi. It cannot possibly go after the painting.
Thanks for your thorough comment. We admit that we may have inaccurcies in dating and labelling artworks. Unfortunately we can't correct them all at once due to the lack of ressources. It seems that you are good acquainted with Leonardo's ouvres. If you'd like to volunteer in putting them in order, please let me know.