[split] Overlap between both "plants" sections

[Koen G]

I think they are mostly by the same hand. Not necessarily the paint, but the drawings. There are a few big plants that make me wonder if some are by a different hand, but overall... I think one person drew most of the plants.

I must admit that there are like four or five large plants that make me think "wait, is this plant in the manuscript I've been studying for a year?"
So I'd accept the possibility of different hands, though like you say there is a large stylistic continuity as well.